Go for 9 Cha + Magnetic Personality. Unless you want to use Mentats and Beer but that doesn't sound confortable.
I can already see you haven't tried 6 CH slaver. Crafting ropes is more annoying than getting a mentat and a beer, really. Even if you don't use crafting alts it's not a problem. Remember slaver has access to all drug shops and usually has a high outdoors. And you won't even use these drugs that often, only when enslaving. It's definitely worth 3 SPECIAL points.
I think the best way to get ropes is to buy gas station base. You can craft ropes there.
Usually this base is near very good slaving spots - Modoc and Redding.
I recommend you a slaver, with thief pretty much all you can do is boring NPC farming or annoying people.
Very soon people will know you and you won't steal anything unless the person is a newbie or has some junk and doesn't care.
Slavers are great to start with - you should have good outdoors, you can do quests and you can even PvP with slaves.