interpretation of passage

It is VERY American English. ("center"). It sounds like it comes from a rather bad novel.

Harry was that way with his life, too - plainly you need to read the text immediately preceding this section, since it is amplified and elaborated upon in the section you quoted. Perhaps you should have quoted it. You are often guilty of this kind of omission, Yoong Liat! Context! The key to understanding!

Everything was right up there front and center - everything was straightforward for him.

[He encountered] open doorways as he navigated through a conversation from one topic to the next - he was confident and able in conversation about varying topics, not finding barriers ("closed doorways", I guess) as the topic changed.

All meshing together - all connecting or interlocking together. Gear wheels are said to "mesh" together.

Since it is usually doors that are open or closed, rather than "doorways", I think we can assume that the author is either (1) attempting to be "writerly" or (2) a bad writer (the two often go together).

Many thanks, Contrex.