English Translation
Being a very particular person he always ties up loose ends whatever he does.
Seriously, no one inserts 読点 (、) so many times like that. It’s unreadable. And why did the author not write the sentence in proper Kanji?
几帳面な（きちょうめんな）means “well-organized” and “detail-oriented”. But the English sentence can be interpreted in a broader way.
My alternative translation is:
彼はとても気難しい人で、何でも片を付けたがる。（かれはとてもきむずかしいひとで、なんでもかたをつけたがる）
片を付ける or 方を付ける means “to tie up loose ends” (see example sentences).
気難しい人 means that “the people stick to their particular styles, policies and preferences, so others cannot play along with them”.