1) Yes. ponglIj means "your name" and the -'e' is not a permanent part of it, but only here for grammatical reasons.
2) -'a' is the question marker. -'e' is a different marker. -'a' is not used with question words, only to turn a statement into a yes/no question. nuq is a question word - that is why -'a' does not appear in this question.
3) In this sentence the suffix -'e' doesn't actually add any meaning, it is just required because you are using the subject pronoun as the verb and so have to mark the explicit subject as the topic instead (which is part of what -'e' does). If you didn't understand that, a simpler, but less accurate way to say it is that when you use a pronoun as the verb "to be" any subject MUST be marked with -'e'.
Be careful -- you have a couple of spelling mistakes.
There is no (capital) N in standard Klingon; the first word is nuq (even at the beginning of the sentence).
The suffix -lIj for "your" has a small L followed by a capital i; you wrote two small L's.
You should hopefully be able to see a small curl at the bottom of a small L ( l l ) that is not present on the capital i ( I I ).
So: nuq 'oH ponglIj'e'? and not Nuq 'oH pongllj'e'?
We are limited in how much we can fit into each Skill's Tips & Notes and this one is full. We cannot add any more information to it.
The sentences presented in this Skill are intended to simply be memorized so that you will have some useful sentences under your belt before you even learn any of the grammar. In future lessons, these details will be explained so that you begin to learn why these memorized sentences work the way they do.