Hey new guy hear but I have been following your forum post for a few months and I thought it was dead when I was reading it last.  I was so happy to know this is still alive and going.  I was even more excited to find out you are considering adding new enemies (ultimate bosses to the game).  
FFVII is hands down the best game I have ever played.  Lots of good memories and every time I play it I get more out of it.  
I am soooo glad you made this mod last time I played it I was maxed out LVL 99  went to the final boss and was completely let down  

 .  I am using other mods with this one and have a made an installation instruction guide based on a torrent I found (I own the game just torrented the mod collection don't worry)  If anyone would like a copy of the instructions let me know.
Right now I am on disk two huge material quest and am having trouble with those damn 1st Class Soldiers at Corel, but don't give me hints I love the challenge(gonna try confuse all next).  
I found a couple of problems along the way:
1. One of the random enemy groups outside Gongaga (sp) with with the earth/based, berserk casting thing (sorry it's been a while and I forgot the name) places one of the enemies right in front Cloud.  Not sure this is happening I think I have a current version of the your mod (I think) , it might also be becasue of the other mods I have installed.  
2. The battle with Jenova-Death gets messed-up if you start using reflect or mighty guard I'm not sure which.  It seems like the damage order get messed up, it was very strange...  When he hits you it forms a barrier on you?  Is this intended, I am pretty sure that you didn't want the enemy to put good status things on you?  Also his fire based attacks are no longer fire based (red light I think) the only one that was still fire based was magic breath also unsure if this was intentional.
Again congratulations on the great work!  I know you be out of town until the 17th enjoy your VA K.  
Ideas for new bosses:  
I really like your idea of adding a Hojo-like boss.  I really think that you should put him or something else in Midgar only available after 3rd disk, it would be an outstanding place to hide an "unbeatable".  Something like a a non-Jenova (because the reunion already happened) Hojo clone born from an extreme Mako bath or something bad-ass like that.  I'm not sure where exactly yet once I get back inside I'll give you some ideas.
I had another idea but it's gone... I'll post again when I remember.