Also, about crafting. These 5 skills, are they equivalent in terms of usefulness? Or there are less/more useful crafting skills?
Ah, crafting skills. They're great, and yet annoying at the same time because the game practically begs you to have all of them.
The most skip-able crafting skills are Biology and Chemistry (unless you use Traps or Throwing, in which case Chemistry is practically mandatory for quality of life). Biology allows you to process heavy creature organs into lightweight chemicals, which can then be turned into useful stims and drugs that are rarely (or never) found and are quite expensive at merchants (if they're sold at merchants at all).
Chemistry is also used for chemical pistols, and both Chemistry and Biology do slip into the creation of a few armor types as well, but nothing showstopping.
Tailoring, Mechanics, and Electronics are all more-or-less equally useful and you will need all three if you expect to craft a full set of gear for any type of character. If you skip one, you'll miss out on being able to craft a thing or two; for example, if you skip Electronics you won't be able to build your own shield generators, shock melee weapons, or armor with powered components. For a gun-wielding heavy armor character, Electronics is the most skip-able because guns aren't electronic (unlike melee weapons, for which you'll need electroshock generators to get the most out of them). Heavy armor requires a fabric lining, and thus Tailoring... yet most heavy armor characters also need Throwing for versatility, and so they need Chemistry.
Mechanics and Tailoring are by far the most profitable. Note however that it's entirely possible to get by with no crafting skills, but the best of every kind of item (particularly customized to your liking) are only available through crafting.
In other words, the crafting skills have their tentacles inside of each other's crevices. It's very Tchortian.
