rabbut
I don't bite, all that often...
The angels can change their out-look on other fish as they mature, so yes they may pick of the betta as they grow, even if they don't when young. When keeping mature angels, you need a single fish, or a group of 6+ or a proven matched pair, otherwise you will get a bloodbath in most cases as they pick on each-other. While having a group of them in there will reduce the amount of time they pick on other fish, if one or more of the group is aggressive (quite likely with angels IME) you will still have it pick on the betta 
For a larger centrepiece, you might want to look at something like a fancy pleco. Blue Phantoms, Snowballs and Gold Nuggets are all nice fish, getting larger at 6-8" (well, actually, there are 6 types of "Gold Nugget", but the most common, L18 I think it is, gets to 8". The other GN's range from 8" to 14") and will let alone any other tank-mate that isn't a pleco. They aren't overly out-going until well settled though, but nice fish all the same. They say part of the joys of owning a fancy plec is knowing it's in there but always having to look to find it unless you've just served it dinner
All the best
Rabbut
For a larger centrepiece, you might want to look at something like a fancy pleco. Blue Phantoms, Snowballs and Gold Nuggets are all nice fish, getting larger at 6-8" (well, actually, there are 6 types of "Gold Nugget", but the most common, L18 I think it is, gets to 8". The other GN's range from 8" to 14") and will let alone any other tank-mate that isn't a pleco. They aren't overly out-going until well settled though, but nice fish all the same. They say part of the joys of owning a fancy plec is knowing it's in there but always having to look to find it unless you've just served it dinner
All the best
Rabbut
