When UR is up, marauders cannot receive any healing.
Remove the stealth part of the aggro dump marauders get but keep the damage reduction and the speed boost if talented.
That's all it would take to fix it. I give you props for actually making a reasonable post.
I don't think removing healing during UR would have quite the impact that many players expect it would. Theoretically, if the mara/sent has a pocket healer that can burst heal them during UR, they should be your target first and the mara/sent no longer has heals. Medpacks would be the exception, but if UR didn't allow for healing, they would just use it prior to UR for the same effect. It's similar to those who argued against reducing sorc's stun down to 10 meters. If you are using your stun correctly (as an escape mechanism or gap creator) then 10 meters is plenty of range and the nerf only affects those who are not using it correctly. I have no problems with making the suggestion you have, but it will only benefit those players who don't focus on the healers first (coming from a healers perspective no less).
As for force camo, it is both highly overrated by other classes and underrated by mara/sents. It is the only way to avoid being rooted to death by snipers without using CC breaker on it. Every other class (aside from jugg/guardian and this is their biggest problem) has abilities that can continue to be used throughout the duration of a root from outside of 10 meters. I'm not saying it is an ideal rotation, but all other classes can do some damage while rooted and at distance. It is an integral part of the kite/antikite dynamic in place at the moment.
That being said, this is not an ability in comparison to what is given to actual stealth classes. It is short duration and they continue taking damage from DoTs as well as any AOEs in the area, so it can't be utilized at the very end right before death. I don't believe this ability can be removed, but I do feel it is available too frequently. It's currently (could be wrong, so correct me if I am) at a 45 sec CD, and could probably increase by about 30 seconds. On my mid level mara, I feel like it is available for use in every fight and I don't think that is necessary.