OK - that's a pretty good set there with some nice action captured. I'm hoping it'll be helpful for me to write a bit on each pic...
1) I can see why you included this pic, but the screening player & ref dont help the overall shot - best to crop them out. The subject himself is nice & sharp. A straighten would be useful to make the pitch level.
2) Nice facial expression - you're getting the impact point which is always photogenic. You've done some blurring to imitate shallower depth of field - doesn't work too well as the player on the right is more blurred than the background and the guy behind him. Best not bother. You need a longer lens to fill the frame though, or wait until the action comes to you. Guess you're using the 70-200 for this?
#3 Good frame filling action, ball & faces in shot. Bit tight on the right side but c'est la via.
#4 The guy on the right is nice & dynamic but is sort of lost in the frame, and the guy on the left adds nothing as he looks like he's out for a sunday stroll. Suggest cropping tighter on the guy on the right and losing the one on the left.
#5 Top try shot - nice one!
Hope you dont mind the "blow by blow" but I found it really useful when I started covering rugby for people to help on each shot. Feel free to ignore it completely