To answer a couple of your questions...
Yes, lots of people have groups of boys that live their entire lives together without a neuter.
And again yes, your boys are acting up because you are away more. In a small group of rats the human becomes the alpha or leader/parent. When you aren't around very much the rats will fight over who's in charge. This is actually normal, think what happens if you leave a group of young children alone long enough... it's Lord of the Flies.
And as to fixing the problem, more supervised play time and rule enforcement would go a long way re-establishing the peace.
As to the risks of neutering, I don't want to cite anyone's personal tragedy as an example, but you might find more information about what happens when things go wrong in the "Over the Rainbow Bridge" section of this forum.
Neutering everyone might help, or it might not... your issue is likely a social behavioral one and not caused by hormonal aggression. Rats are social animals and they need a stable hierarchy in which to feel comfortable. Some folks with large groups tend to cultivate a "head rat" as their enforcer, with smaller groups it's best when the human is directly in charge.
I realize that as humans our situation changes from time to time, but rats aren't designed to cope with absentee leadership very well. It's both the benefit and drawback of owning social animals. Dog owners often have similar problems when they change their life styles and their best furry friends start fighting or tearing up the house. In nature a pack alpha would never be more than a squeak away, that's not entirely always possible for a human alpha, but if you can get in enough play time and try and maintain discipline your rats can get used to you being away more than before.
I'm home a lot so I can stay pretty hands on, but I do support one rat above the others when we have more than one. Our "family rat" is always fed and called first, she's always first to be let out of the cage or offered to go outside on field trips and I back her in fights, so even when she gets older and weaker she can count on me for support, this helps to keep order when I'm away. When our family rat passes away, the job goes to the next in line. I know it can be unfair, especially when the younger rat is brighter or more gifted, but that's what works best for me.
When our big old girl Fuzzy Rat became completely debilitated due to multiple massive tumors, she would squeak for help when she didn't get her way, and I'd go defend her, this way she could still be the family rat when she was faced with much larger and stronger competition, she knew I was there to support her as did her roommate. I don't know if that will help you or if you just need to put in more time hands on, but sometimes kids and rats aren't easy.
Best luck.
