Sentence 2

My sentence: "Having invited me Finny now felt he had to keep me entertained." Gene said this on the way they were riding to the beach.
1) Wednesday, Oct 3rd, 2007
2) A Separate Peace
3) This sentence start with "having invited" (I don't know what's the name of this form, though), combine Finny's invition and his feeling together.
4) I like this sentence because this is a new form for me, and I will try to use it in my writing, instead of always using the same form to express a sentence. (I used to write like "Finny invited me and felt he had to keep me entertained" in this case)
5) My new sentence: Having done my homework, I now felt I need to have myself relaxed for a moment.
Question: Why is it present tense after the word "now" ? Can I say "Having done my homework, I now feel I need to have myself relaxed for a moment" ?

Sentence

My sentence choice- "Because, unfamiliar with the absence of fear and what that was like, I had not been able to identify its presence." Gene said this when he was walking in Devon School.
1) Tuesday, Oct 2, 2007
2) A Separate Peace
3) Sorry, I don't quite sure about what are the comments about the grammar of this sentence. I will be appreciate if you can give me some guides.
4) I spend a lot of time to figue out what this interesting sentence, which I think it's a litte bit confusing and complicated, means. This kind of sentence structure, which I never seen before, caught my eyes when I saw it. I think it's a good way to express what you want to say instead of a simple sentence structure if I can control it.
5) My new sentence: Because, unfamiliar with the look of his old school, he had not been able to identify its new look after rebuilted.