Some questions remain about his explanation.
I would be glad if I could be of even a little help.
A polite request word used in set phrases such as 何分よろしくお願いいたします. It feels formal and somewhat old-fashioned; 何卒 is often a stronger or more standard formal equivalent.
I sincerely ask for your continued support.
anyway; at any rate; after all
Often introduces an explanatory reason or excuse, close to 'after all' or 'given that ...'. Common in polite or written explanations, especially before clauses ending in ので.
Since this is my first time after all, it will take a little time.
It was all rather sudden, so I could not prepare enough.
I've been assigned to a new department, so please be kind to me.
Since this is my first time doing this, I may make some mistakes.
It seems his story contains some degree of truth.