1. The opponent can just spam "attack X". There is no downside to doing so, as even if you spam a few times past successfully dragging a person into combat, nothing happens - just a message that you already are attacking them. Maybe after failing combat initiation, there should be a cooldown before it can be issued again? Would make attacking those shifty people a bit harder, and more relying on IC skills, rather than OOC command spamming.
2. Aim at X seems to always succeed. Another way is to first aim at a person, and then attack them, and that seems to work around the evasion. I think Aim at X should go through the same checks as Attack X to see whether you were successful in stopping the said person, though maybe a slightly lower difficulty, and making the "flee" from aim a bit easier than "flee" from attack.
Let me know what you think! I just love the evasion idea, and think whether someone succeeds in attacking you, or not, should depend on Character sheets, not command spamming/using them in aim/attack chain.