1. The previous year's stuff requires lower begging - but you can get there in a few hours of begging (note that trick or treating does not count as begging). Usually only the new items for this year requires the character to have GM Begging. Finding someone to buy Begging from is hard, but worth the effort if you find them (I forget where I found the NPC - see if the red NPC in skara mainland offers it, as I think it offers most skills).
2. When training begging, consider keeping the water pitchers, then once you're nearly full of them (having dropped/trash the rest), go find a water elemental and throw the water pitchers at them. The "Endless pitchers" that the water eles throw back into your pack are worth the effort for a returning character. (you link to a trough or other water source in your house, then you can cook and water without having to reload it)
3. The candy apples for trick or treating can be used for feeding pets that require fruits & vegetables, without having to pay through the nose (cooks and tamers have gotten apple's price to 50-100 GP each off most NPCs, from a start price of 3)
4. The skeletons with the potential for character skeletons are all skeletal/bone knights - some with character names, some with the default ____ knight name. You can tell the difference because these have thousands of HP and run faster than an Ilshenar Paragon. They also are bit more damaging (not much - more a factor of higher dex meaning faster attacks). They CAN swarm you. If a skeletal/bone knight is going normal speed, you can ignore it, as it means that it was a summons or animated one, and won' t have any loot you'd want.
5. The Butchers in the Graveyards are relatively tough fights, but faster than fighting several of the named skeletons at once. They summon undead up through liches (including those annoying regular bone knights), and have the carving kits for the regular jack-o-lanterns (not the trick or treat drops), with the pumpkins for carving coming from the large pumpkins spawning Grims in the farm fields.