I feel this problem is more due manufacturing consideration then a straight design flaw.
The reason the spring is there is because silicone conductive pads that cover the actual trigger mechanism. It's meant to relieve the work load on the pads. True that if you take the spring out you don't really lose functionality but what you are doing is putting all the work on the pads and cause more wear and tear on it and will eventually need to replace that too, especially if you say you use them quite often.
If the little plastic piece on the hinge breaking is the cause of the stickiness you are better off just spending a few bucks on ebay for another R2 button and replacing the whole thing. I did that and cleaned out the R1/L1 area and it's been working like new for a while now.
This is a much better solution that doesn't require you to spend too much money.