Different ways to refer to oneself (2-in-1 question)

Question

I have two questions about ways to refer to oneself in Japanese. Since they are so closely related I am posting both in the same thread but if anyone here strongly disagrees with this please let me know and I will split them up into two threads.

So here goes:

(1) I know one does not refer to oneself as XY-さん but rather as XY. But does this rule also apply to ちゃん? I'm asking because some of my friends call me ナッちゃん but using the general rule of just using my name this would leave me saying stuff like ナは今帰る。Since this sounds wrong to me I have been saying stuff like ナッちゃんは今帰る。

Is it normal/okay/natural to refer to oneself as XYちゃん?

I don't absolutely have to use ちゃん since I could just use my full name but that's more of a mouthful.

(2) I'm female and usually male individuals refer to themselves as 僕 when talking to me. Once I did a homestay and the host father referred to himself as 俺 when talking to me.

When someone says 俺 it makes me think that they are kind of common and I don't like it.

Is 俺 really a rough word to use when talking to someone of the other gender who is not an extremely close friend? Or is it good practice and I should not mind at all?

Answer 1

I'll take a stab at it.

1. I would say not really. Since you say you have a long name and your friends call you
   ナッちゃん, that's already a short form of your name and using that to refer to yourself may make you appear childish (as mostly young females refer to themselves in third person, unless you're going for that young person vibe). Stuff like ナは今帰る sounds awkward because it's kind of like referring to yourself by your own nickname. It is much easier convenient and would make more sense to refer to yourself as simply 私; thus 私は今帰る. You could also replace 私 with your full name but if it's too much of a hassle (from the length) then don't.

2. I'm not sure what you mean by "common" but yes, it is casual in general, not just to the opposite gender. 僕 and 俺 are both ways boys refer to themselves. 僕 is a more formal and polite way that young boys or teenagers/men who want to sound polite.
   
   俺 is a very casual way that boys/teenagers/young adult men refer to themselves. It is mostly used between close friends and can sound rough to people meeting for the first time. I wouldn't say good practice per se but it is normal for the host father to refer to himself as 俺.

Personally I use 俺 a lot but in super formal situations I use 私. There's an article here that explains how to address yourself and other people that you may find helpful. http://www.guidetojapanese.org/learn/grammar/people