Before even critiquing I do have to say one thing...you definitely *cannot* be offended easily if you expect to make it in the photography world. Most people are kind and helpful, but those are usually the people that don't offer the best help. If you truly want to succeed on some professional level you're going to need to learn to take critique (no matter how harsh it seems) or you're going to implode...because the people that hate are *definitely* the people with the loudest mouths.
On to the critique:
1) As others have said, it's a very 1980's cliche shot. It's not a bad picture by any means, and it's exposed correctly...but it doesn't convey much emotion because most of the people that see it will immediately be reminded of the 80s and how many pictures were done like this. Also, the church seems to be at an angle.
2) This is the one most people are jumping on and although on one hand...for somewhat good reason...on the other hand, it's *very* easy to fix. I saw your later edits and they're much better (definitely no selective-coloring because you want the focus put onto the rings most of all), but some of it you can't really do in PP. The biggest thing, as was said, is that the focus was not put on the rings. This, I'm sorry to say, is somewhat essential for pics of the hands like this. Even glimmer could be added in PP.
3) Not a bad picture, but looks like you surprised them. The exposure is *almost* correct, but a tad dark. The lighting (other than exposure) is pretty spot on. Definitely try to stay away from the "at an angle" approach. Too many people do it and too many people do it incorrectly. There aren't really any rules for it (other than avoid it), but it *can* be done correctly...it's just all about the scene and whether it works for *that* scene, specifically. This one it didn't. Other than that, make sure to nail the focus on the eyes of the subjects (in this case with a high-enough f-stop to capture both sets of eyes in focus or even take 2 pictures [one focused on each person] and try to blend them in PP) and make sure to take control of the way they sit/model. As the photographer you need to direct them to get the perfect shot, because everyone knows they won't do it on their own.