If you choose to agist your horse with other horses that's just something you have to deal with.
I don't like using shoes on a horse unless they need it for some reason which in my experience a large proportion of horses don't. Sure if you are riding them hard everyday to the point they are wearing away quicker than they are growing, or for some other reason they need it then sure. But in my experience horses go better without them (once they have adjusted).
I have had my horses shod before and I do it all round, I wouldn't only do it on one set, in my mind (not based on hard evidence) the horse would be unbalanced - I wouldn't do it. If you are going to do two you may as well do four.
Leave a rug on your horse - a stiff canvas should deflect a fair few of the "cutting" kicks. Also, if you determine that there is an individual horse that is causing injury to multiple horses in the paddock then speak to the owner - I fully believe that people with horses that are known to be damaging consistently to other horses should not be kept in paddocks with horses owned by others.