Hi there -- I've written about impressment before, and depending on the time period you're interested in, the answers might change. In general, if you were an apprentice and not a seagoing man, you would not necessarily be "targeted" for impressment, but during the Napoleonic period when ships were desperate for men, you might just be caught up in a general press.

You could absolutely return home after a voyage -- there was no such thing as permanent service in the Navy for an enlisted sailor, or even for most warrant officers (though some sailors would spend their lives in the Navy by volunteering again at the end of a commission).

In terms of impressment improving your life -- well, it depends on what it was like before. If you were lucky enough to serve under a good captain, a sailor's life could be quite interesting. Although wages were not as good as those in the merchant service, sailors were generally fed well and provided with clothing and (granted, often quite wet and uncomfortable) shelter, as well as a pension if they were injured in combat.

Here are those older answers:

https://www.reddit.com/r/AskHistorians/comments/2oo91z/during_the_age_of_sail_how_reliable_were/

and

https://www.reddit.com/r/AskHistorians/comments/2xwhrj/how_did_press_gangs_determine_eligibility_for/

Let me know if this is what you're looking for, or if you have follow ups.

Bonus round, could I be impressed by pirates or would I have simply been kidnapped/murdered/ransomed?

I wrote another post here about how sailors were sometimes forced to join pirate crews. They would never have been captured by pirates like this while on land though.