I can understand what you are saying Alia. From my experience with a male and 2 female swords, the male spends all his time chasing the females and they in turn spend their time getting away from him. I have kept smaller tanks as well although never having had swords before as I always shied away from livebearers (those are Les's babies). I never had a lot of problems with what most people term aggressive fish. My biggest problems were the zebra danios and dwarf gouramies. Those would tear up any fish I put in there with them! There again, it all goes back to personality. I don't recommend neons with larger cichlids or any pictus because its a given that someone is going to turn into a snack, most likely the neons. lol
With that said with most advertised "community" fish it is about trying out fish. I have had to take fish back to the lfs more than once or move them to another tank because what everyone said wouldn't be aggressive turned out to be the worst in my set up. Most of our fish in the 55 gallon stay together......looking at it right now they are all on one side. These include......3 clown loaches (small) 5 large black skirt tetras, 6 serpae tetras, 3 tiger barbs, 2 green tiger barbs, 2 tuxedo platys, 1 red wag platy, 1 lg. red sword, 1 albono cory, 1 green cory, 1 marigold sword, 1 pleco and the 2 newts who hang out behidn the air tubing most of the time. They all get along really really well. The clown loaches school with the tiger barbs and are so cute swimming around playing with them.
All I really want people to understand that with a little common sense you can keep different types of fish together, everyone's experiences are different. I don't want to hurt feelings, just not discourage people who are new to the hobby. I hope I haven't offended anyone as that is never my intention. I love keeping fish, if I didn't, I wouldn't have 5 tanks running and another waiting until we get moved to get set up and another waiting for me to pick it up! I only want others to have as much enjoyment as I do.
With all of this said, with the size of the tank, I would recommend about 4 females to one male sword. This should definitely curtail any nipping as they will all be busy! I don't care for bettas in a community tank personally. I think that bettas are beautiful fish but they are weakened greatly from a century of inbreeding to get the long flowing finnage you see today. Even breeder recommend breeding brother with sister to get more beautiful colors and finnage! The true bettas are not pretty fish to put it bluntly. They are not colorful and have very short fins and tails as they are aggressive and this allowed them to survive in their natural surroundings. A search on bettas will prove this. They were bred to fight and you never know how they will be as some are quite docile creatures while others still have that instinct to fight anything in their territory. The inbreeding makes them more susceptible to diseases as well. I would quarantine a betta before adding it to a community to ensure that disease isn't brought in to your other fish. I used to keep them but in recent experience have been unable to keep them alive. The ones you pick up at pet stores are at least a yr old in most cases because that is the age at which they have fully developed finnage and color. With a lifespan of 2 yrs, it doesn't seem likely to live for long after you buy it, depending on how long it was in a "holding tank". This is just my opinions and experiences. Take it as it is or leave it, everyone is entitled to make their own opinions!
Allie
. The only thing you can do really in the fish keeping hobby is to watch your fish closely when introducing any new ones. Fish, like humans, dogs, cats, etc. have personalities and some that everyone says are gentle, docile species will surprise you and terrorize everything in your tank. Its all a game of trial and error. Just try to have a "time out" tank to put them in until you can decide whether the aggressive ones need to go back to the lfs or if an occasional time out will calm them down. This is my opinions but all others should be taken into account as well.
The only time you'd get trouble is a ratio of 1:1 or 2 males to one female in which case the female will get bullied and the stress after time may kill her. 
hey playfull do u keep your newts in your fish tank with your fish? If so tell me how I can Keep some in my tank 
