Opinions on Cover Text

In 2 and 4, I have a hard time reading the word "Bob."

"None of them" isn't an option. 1 and 4 are very difficult to read, and the faux-Star Trek text just doesn't look very good in this context. The use of the lower case at the top when the rest of the page is upper-case looks out of place in this font, which demonstrates that it's not a well put together bit of type design. Ailerons is a decent sci-fi free font, it's a different font to what you have but it's also not an obvious rip of the TNG title font - especially in that blue. Unless its a parody of Star Trek, change the text.

Setting the text without the image is fine, but you might find that once you put in your desired image you'll have to change the text anyway. If it's hard to read on a plain black background it'll be even harder with noise behind it.

Text alone, # 2 and 3 is the easiest to read, the parenthesis makes 2 more difficult--but that may change when the image is added.

Differentiation between title and author needn't be handled in any way other than using different sizes, and often even that is unnecessary. Unless your book title is a person's name there would be no confusing between what is title and what is the author's name.

Looking at the site, you're right, Ailerons is for personal use only. That was a bad suggestion, apologies. Though I would say you don't need a "sci-fi" font, a simple sans-serif will do the job perfectly well - especially a geometric like Futura or Gill Sans if you can get your hands on them, otherwise fonts like "Moon" https://www.behance.net/gallery/23468357/Moon-Free-Font or Manifesto https://www.behance.net/gallery/21065399/MANIFESTO-free-font can give the same effect. Fonts with near-perfect circles for "o"s are the ones to look for.

If I were in your position, I would steer clear of the typeface you're using as it somewhat forces you into certain lock-ups - for instance, the faux italics centred would look garbage. Chances are your image will be more than sci-fi enough, try and go for a more professional typographic look - after all, the most important thing about the text on a cover is readability.

As far as the brackets go, it's not poor form to use spaces or half spaces between bracket and text. If you would like to use them but find it difficult to read, that is an option. Though with a better selection of typeface it is unlikely it would be a problem.

Finally, careful of leading. In that final option the "We are" and "Legion" are too close together, it's uncomfortable. Then the "We are Bob" is too far away to be part of that title and not far away enough to be a subtitle. A consistent leading between title text would come across much better.

#5 is the one I pick from all 5. Is We Are Bob part of the title? #1 with the shadow effect is not easy to read. The ones with the strikethrough are easier to read but not pleasing to the eye.

My first impression of #5 was "What the heck is a BOOH?"

I personally prefer version 2 or 3. Hard to say which particularly though, without the image to go with it.