My first question is: do you and the other players have any say in all the house rules being introduced into the game? If not, it sounds like you have a pretty tyrannical DM. I'm quite fond of a few house rules but I always discuss them with the group ahead of time. Sometimes I get the group to adopt them as is (even if only on a trial basis), sometimes we have a brainstorm and come up with a compromise, sometimes they just don't like it and I have to decide whether my preferences are worth forcing everyone else to play a game they don't want to play ('no' is the standard answer there btw). Maybe its time for a round-table discussion with the whole group to try and get some consensus. The idea is for everyone to have fun of course, not just the DM (or players for that matter).
It sounds like you have a really cool character concept that I'd welcome at my gaming table but I think I'd share your DM's worry that regularly taking advantage of your fellow players/PCs would ruin the fun. The difference is, I've always allowed my players to use their abilities on each other's PCs so I wouldn't stop you using the powers, but I would make you live with the consequences. 
When you cast Charm Person on an NPC, you're usually gone before the spell wears off and they start to wonder why they liked you so much. There's nothing in the spell description that suggests they forget their feelings or what transpired after all. When you use Charm Person (etc) on a PC however, you tend to still be there when the spell wears off. You might be able to get away with it if you do so rarely, but once your fellow PCs start to understand, or even just suspect, your powers, they're going to get really, really suspicious. That opens the door for circumstance bonuses to saving throws, something already available and entirely up to the DM's discretion (when he remembers to allow it).
You might suggest to the DM that he allows you to use your powers against PCs, but, unless they're extremely distracted (in the heat of life or death battle for instance) every time you do it gives them a cumulative +2 circumstances bonus to their saves (open negotiations without the 'cumulative' part to let him 'win' a concession from you if you want to be crafty). With any luck, your DM might see it as a workable compromise. You'll get to use your powers enough to generate a few interesting roleplaying moments amongst the party, and your fellow players (hopefully) won't feel they're getting excessively taken advantage of. 
Reminds me of a time a cleric PC of mine became suspicious of the PC rogue in the group (after a number of incidents). I challenged him to answers a couple of questions under the influence of a Zone of Truth, thinking if he failed (as I was confident he would), my cleric could make it his project to help the wayward halfling repent of his wrongs. The other player apparently thought I was leading up to killing his PC so he refused the challenge and bolted from town on the first horse he could find. Turns out the rogue was pilfering a lot more than I suspected (courtesy of notes back & forth with the DM). Made for a very interesting session. If the rogue had thrown himself on the group's mercy it would have been even better.
