Actually, it's TEN properties (would be 9 if it could be imbued, from Self Repair dropping off).
Mark of the Travesty
Weight: 2 Stones
Property 1: +10 Random Skill
Property 2: +10 Random Combat Skill
Property 3 (would drop off if it was imbuable): Self Repair 3
Property 4: Mana Increase 8
Property 5: Hit Point Regeneration 3
Property 6: Physical Resist 8% (base is 3%)
Property 7: Fire Resist 5% (base is 0%)
Property 8: Cold Resist 11% (base is 6%)
Property 9: Poison Resist 20% (base is 10%)
Property 10: Energy Resist 15% (base is 5%)
Strength Requirement 10
Durability: 20 / 20
So, the 5/5/5/10/10 extra resists will count as 5 properties. Any non-crafted item with non-standard resists is treated as having magic properties for the resists that aren't standard for a non-magic, normal quality, item.
No, there's no risk in trying but all that will happen is you'll be told it's not possible, since you can't imbue anything that has 5 properties other than Self Repair (And even at 5 existing properties, you could only alter what was already present).
The total intensity of the Mark is 2/3 + 2/3 +3/5 +1 +1 +1/3 +1/3 +1/3 +2/3 +2/3 = 2+11/3+3/5 = 5+2/3+3/5 = 5 + 10/15 + 9/15 = 6 4/15,
or a little over 625% intensity, and would STILL be 566.67% intensity without the Self Repair - and since the mark is a non-crafted item, it would be capped at 450% maximum intensity when imbued. - so you'd need to reduce a 1.4 weight item to nearly 0 to even successfully start altering properties.