Absolutely. Internal linking can be very subtle and could influence the flow of authority through the site, and hence even shifting a couple of links may make certain pages more effective.
Yes, a title can make more of an impact than you would think, particulrly in regards to click through rate. If the number of impresions remains constant but the number of clicks increases dramatically, this is a good indicator that the previous title was limiting the page.
Yes, that’s right. Typically, I start with the weakest part, be it internal linking, intent or information gaps. Sometimes small fixes are better and safer than a complete redesign of the entire page.
Yeah, especially with internal links. I added a few relevant links to some older pages once and saw a bit more improvement than I expected. It wasn't anything major, but I could definitely tell there was a difference.