Translation assistance please! :)
 

I recently got a japanese pen pal and I'm having just a tad bit of trouble clarifying exactly what she means by some things, most things i understand, but it's a bit more casual than i'm used to, so I just thought i'd ask for some help on the things i can't understand.

私でよかったらにほんごおしえますよ
is this along the lines of, "I will teach you english well?"

あっでもかわりにえいごおしえてくださいー
is this, speak instead in english? I can't really figure it out

長くなちゃってごめんなさい
i picked up length and sorry here, but i'm not quite sure :/

あと、敬語(~です。とか)やめちゃってください
i'm pretty sure this is like, you don't have to use honorifics?

Thanks for any and all help :)

私でよかったらにほんごおしえますよ
is this along the lines of, "I will teach you english well?"

Yeah. More precisely, "If you find me good enough for it, I wil ~~~~." It does not say "well".

あっでもかわりにえいごおしえてくださいー
is this, speak instead in english? I can't really figure it out

"And in exchange for that, please teach me English."

長くなちゃってごめんなさい
i picked up length and sorry here, but i'm not quite sure :/

"Sorry about the long (message/letter/email/whatever you're using to communicate with this person)"

あと、敬語(~です。とか)やめちゃってください
i'm pretty sure this is like, you don't have to use honorifics?

Right. "Please get rid of the polite speech such as "です"."

私でよかったらにほんごおしえますよ
is this along the lines of, "I will teach you english well?

Where are you seeing "English"? It's an offer to teach you Japanese.

あっでもかわりにえいごおしえてくださいー
is this, speak instead in english? I can't really figure it ou

In exchange she wants you to teach her English.

長くなちゃってごめんなさい
i picked up length and sorry here, but i'm not quite sure :/

She is apologizing for the long message.

あと、敬語(~です。とか)やめちゃってください
i'm pretty sure this is like, you don't have to use honorifics?

She is asking you not to use polite language, even though she is here in every sentence.

Good point.

We posted about the same time. Thankfully I did not contradict you.

I guess I should point out that the first sentence says "Japanese" not "English."