Problems with this sentences grammar

Question

For more context, see this doc: https://www.docdroid.net/qteAJpo/img-20170628-0002-new.pdf.html

The sentence in question is the following from line 5 to 6: 自分にそんな質問をして、それに有名作家になったつもりで答えるんです。

First Im confused by the use of tense here. Why is there past tense used in なった here, while we have present in the main clauses predicative 答える, concerning the context? The author is telling about his past habits of constructing fictional interviews with himself as the interviewee. So I'd rather expect the tense in both the subclause and the mainclause to be past tense, at the utmost I'd expect the subclause to be in present tense like it would be in english (okay in english its actually an infinitive, but its at least the infinitive categorized as the infinitive of the present tense ^^): "..., in addition I answered that I plan to become a famous writer."

Second, I don't know about the で after つもり. Is it the particle で, is it a shortened version of です? Considering that the subclause ending with つもり somehow needs to be embedded into the mainclause, I'd rather say it's the particle: "..., I answer with intent to become a famous writer." This has it's own caveats though, because I've never seen this before outside nominalizations with こと/の, which clearly can be used to nominalize a whole subclause. Just putting で after つもり could be interpreted like this as well "...,I answer with the intent of becoming a famous writer." but this would obliterate the lines between the subclause and the mainclause, unless I wrote: "..., I answer with the intent, that I want to become a a famous writer." which again assumes structures which arent explicitely shown in this sentence.

Answer 1

"Intend" is not the only meaning of つもり. Its basic sense is "what someone has in mind", "what someone is thinking of". This may be an intention, a supposition, an idea, a hope, a presumption, an impression, etc. The pattern illustrated here (つもり+ Particle で) can mean not only "with the intention of", but also "with a sense that", "on the assumption that". Here, the speaker is a famous writer telling how, in the days before he was successful, he would pretend (ごっこ) that he was already famous and that he was being interviewed by a journalist. He would ask himself what it was like when he was poor and unknown and answer in the persona of the best-selling writer he hoped to become. The sentence means "Asking myself such questions, I would answer on the supposition/assumption that I had [already] become a famous writer". A bit more idiomatically, "I would ask myself questions like that and answer them as though I were already a famous writer".