I really
love 
what you're going for with these. It's a super neat idea, so kudos there. I wish more things existed in the game that were similar. For example: I had hoped cursed cards were legitimately powerful, but with very real drawbacks. In the end- they were just grindy and boring.
These feats are fun!...potentially.
That trouble is- DDO as it exists today is an unfriendly habitat for things that immobilize you for 6 seconds etc. But that's because higher difficulties are the norm (perhaps it shouldn't be so), mobs hit
very hard on those difficulties, but also because: there is a feeling of entitlement from many people that remain playing DDO today, that they should be able to complete quests/raids with barely the hint of a hitch or disruption, in this endeavour. After all- XP/min is sacrosant (perhaps it shouldn't be so either). So of course it won't go down well.
I'm sorry if that comes across as harsh to my fellow players, but it is just what I've observed. The possibility of failure is much more palatable to people in other games, I've found. Often, that possibility
is what makes those games thrilling and replayable.
Speaking of raids...People don't want to be blamed for causing them to fail due to something like immobilization or slows happening at inopportune moments. I don't mind the risk, as long as the chance is quite low. And I agree with the calls for letting us know the true % of it occuring.
The issue, to me, isn't these sort of bargain mechanics existing. I think they are interesting and creative. Definitely. It's more the state of the game, and the community therein, that is hostile to such concepts. It is the latter that needs realigning, in my humble opinion.
I think a good start would be to buff the feats. Go crazy with it! Make them actually tempting. Not every one will want to use them, no matter what. And that's okay.
But right now...there is not quite enough draw, to go with the drawback.