I think PVP is definitely doable. However - it will never be what it should be without a PVP dedicated dev team to manage it. It really comes down to having the proper people in place at that level with no strings attached or absurd limitations etc.
Details..... well here is what I'd recommend.
#1. 'Twitch' PVP - If you allow what I call 'overly precise, high speed gameplay' also known as 'twitch' to dominate pvp - then scripters will always win - this will kill interest in PVP for a VERY LARGE NUMBER OF PEOPLE. It isn't about banning some 3rd party progs although that may help. Nice idea but it won't work. Better idea is to alter game design very slightly to eliminate the incentive for their excessive use - naturally bringing back a good balance to PVP by allowing a player who DOES NOT USE THEM to compete very well against those that do. THIS will work and it will draw people back into PVP for sure.
#1a Generally speaking, you must NOT allow combinations of moves to be used by a script that could not be easily replicated via a normal macro. The way to do that is to 'design out' the incentive to use scripts in pvp. There are many creative and effective ways to do this without ruining any skills whatsoever. What we see by EA in general (hard to comment on Broadsword) is a lack of effort and interest in doing so - and this is the larger issue, NOT weather it can be done or not. YES IT CAN BE DONE AND SHOULD BE.
#1b The use of shurikens/darts , potions, enhancing items, changing suits in mid horse stride and all similar issues. Eliminate the incentive to do this stuff in pvp. This is not that hard to fix. Simply put more cooldowns on using this stuff. Potions should be relevant but not DOMINANT. Changing clothes/skill items should TAKE TIME - not be easily done quickly back and forth over and over. Perfectly timing throwing potions on targets etc should be curtailed/simplified/improved so that scripts have ZERO advantage over a regular player in practice. THIS IS VERY VERY DOABLE.
#2. Spell Spamming. In the old days this was how you killed people. Make this difficult to do at least in the sense of pay more attention to spell timing. Some spells really need to be sped up,
others should be slowed down a bit. One way to eliminate this issue is to increase spell damage on some spells and slow down their casting speed - this makes them useful without making it easy to just spam people to death with them. The combination of this will help maintain a healthy pvp balance. When the speed is too fast, it makes it impossible for regular players who arn't using scripts or have super fast pings to compete with those that do. Yet players just making normal macros could easily compete against scripters if this was more carefully balanced. This is an SIMPLE change that could be done relatively quickly with enough testing. The notion I expressed here will give a net gain to the regular player against the scripter.
#3. Bring back combos. The whole 'can;t have special moves up while casting' is stupid - this would even help wrestling and can easily be handled via normal macros. This is what made pvp fun. If something is overpowered - merely semi nerf it for pvp, but don't destroy it or prevent people from comboing - this is idiotic. I understand why they did it, in a way it helps people learn what even is happening to them, theoretically and I sympathize - but ultimately combos should be brought back - its better for pvp and MUCH more fun, especially if the other issues I mention here are addressed.
#4. Poison - I can fix this easily. In the old days of UO - you could heal through poison, but deadly and lethal poison would do ALOT of damage even if you did heal, this was great! Much more interesting yet still allowed teams of people to keep a person alive while people tried desperately to cure lethal (From poison ele's). There was not some cheap - cheesy way that prevented crosshealing. I always felt this was silly and there should not be that many moves that prevent healing alltogether. I understand why its setup the way it is now but my idea is much better IMO overall. PVP was always about being able to do alot of damage in different ways , not hitting each other with random junk and saying 'well met sir player you hit me for 10 damage hahaha'. What a joke.
#5. Item insurance. There is alot I could say about it. I have thought about how to deal with the current dilemma. I believe it should be changed to 3-4 items only on a person at a time.
Why this much? Simple. At this point in the game there needs to be a balance between item insurance and lootable items. Also because of item insurance - everyone MUST have an uber suit to even PVP or else you are at a disadvantage - way too much of one IMO - no wonder people hesitate to get into PVP. This is a debatable point but its my preference. By having some insurance you allow people to have what they love - a few items that they are attached to and will not lose - whoo hoo! An identity they can keep - without losing their favorite weapon or helmet or chest armor or gloves or ring. However the rest of their stuff is lootable - meaning they will have to be more strategic/efficient in what they use/take into pvp. This will make pvp more attractive without ruining people's attachment to their own unique setups - which since they can have 3-4 items insured are still easily possible and relevant.
In addition, my idea would allow an infinite combination of relevant equipment. Right now you will always end up with a cookie cutter sooner or later. Using my idea (this idea), that goes away quickly. Whoa to the item sellers hahahaha.

But don't worry you'll still be in business.
#6. Mortal Blow etc - simply put - make Mortal blow impossible to remove (Sorry paladins) and make the cooldowns on enchanted apples 5 minutes. These are meant to be used in special situations - not spammed to prevent game effects from even being used. Silly the way it is now IMO (debatable perhaps due to boss monster curses? you tell me).
#7. Allow paralyse fields to be more effective against tamed animals - this will prevent pvp tamers with 'spamming people' with monsters - auto follow etc as easily. Therefore you will have to manage your beast well - no cheap thrills against anyone that knows anything. Don't like parafields? Dispell em.
#8. Why should people pvp if there is no incentive? The previous issues I've mentioned cover some of the issues as to why people won't even try it. Why is it that there are so few places people can even practice pvp without putting in a substantial effort to set things up? Exactly. The game has gotten too item based - this wastes TONS of time. Whatever $$$ EA thinks it makes by making the game this way also COSTS THEM customers who would otherwise pay the near max. Counter productive assumptions are/were made because lazy business people wanted to make UO 'automatic' instead of a living game. Honestly some business people (not all) would not understand this games potential if it slapped them in the face. Huge problem which we don't have time to correct but worth mentioning.
#9. Its silly to have people running around with whole backup suits of armor for 'situations'. Great job by the player to innovate and use that, TERRIBLE job by the company of forcing people to do that! Idiocy. More skill based, less item based (but still plenty) is the right way to go. If you take my item insurance idea it will TOTALLY GUT that way of doing things. Of all my ideas I like #5 the best personally. If some people dislike it - fine I would allow full item insurance in trammel, but ONLY 3-4 items will remain insured in FEL. Yet FEL will have better rewards. Choose wisely.
Conclusion : These are just some ideas gathered over many years of watching UO PVP. I did not cover everything so do not take offense. Nor are these ideas perfect. Otherwise, feel free to comment, thanks.