Yes, having 2 FB/BYM accounts is against TOS. But if you're serious about gaming, it's a must have imo. There are too many advantages from having multiple accounts to ignore. First, just having the ability to help out on your buildings is a big plus (especially with the increased upgrade schedule for towers). Secondly, you can make sure you get your daily gifts. Also, once it gets to Lvl 2 Maproom, it's like having two main bases in your empire.
Finally, it gives you new mobility. Whether it's to play Avenger in your own empire, help an Alliance member that is in need somewhere else, or to take part in epic PvP wars like what's going with James Bower. In addition, they've just changed it where you can upgrade to lvl 2 maproom with a Lvl 6 TH. Even so, it still takes a little while to do (prolly 4-6 weeks of leveling) because they've changed the costs of upgrading. And maybe 8-12 weeks to get it competent and battle ready.