My opinions only.
Stay away from the scandium/unobtanium revolvers. They carry great, but they will shy you away from practice and I am not recoil shy.
The extra weight does make a difference but to me not enough to matter. Again this is for me only. The weight might drive you crazy. Try before you buy.
.357 out of a snubbie is more powerful then .38+P but the advantage gained is not as big as if it were a 4-6 inch barrel. This extra power, although small, and the simple versatility of what can be shot sells it for me.
The extra few oz. make a huge difference in follow up shots and shootability but I might just be a big pus....ahhh girly man.
Ahhh the lock. I don't think you have an opener big enough for that can of worms. Yes the lock has malfunctioned. Yes I do not want the lock. That being said based on my research the statistical chances of the lock failing are probably up there with any other part failing (ammo, firing pin hammer spring etc.) Do your research and make your own choice. For me I decided to go no lock in my revos. This choice is due to aesthetics and principal more then mechanics. But be aware the locks HAVE INDEED FAILED. This is just food for thought, not a statistical absolute.
Removing the lock is absolutely easy. The problem is or may be the fact that a lawyer may attack you for this making you look like a maniac. Now again chances are they will attack you for any number of other things as well so this is once again one of those personal risk assessments that is a personal choice to you.
Me I am a no lock kind of guy, although the statistics, risk evaluation person I am in real life (job) knows that the lock is likely pretty benign (although ugly). The gunny in me sees it as both another poorly designed item to go wrong and a sellout so I will not own one. You pays your money and takes your chances.
I personally think (lock or no lock) a Smith 642, 442, 638, Model 60, 640 or 649 are just about perfect for self defense firearms. I am still not sold on those uber light hand grenades though.