I'd say "no" to both, but YMMV. They struggled with the launch (their server wasn't able to handle the capacity, but they eventually upgraded it), and they are only providing minimal updates and some critical fixes. As far as I can tell, they haven't added anything new. I don't think Fawkes Games has the resources to make the game much better than it was.

My own personal experience is that it doesn't crash too much (like, maybe once or twice out of 10-15 hours of playtime). Sometimes it could be server-side or client-side or network related. Best place for updates (ie. to check server status) is their Discord. There's a subreddit, but, I don't know if the devs participate or not ( https://www.reddit.com/r/Defiance/ ).

You can play for free, but, there are some limitations (eg. inventory space) that you will come up against fairly quickly. They have a the standard store thing where you buy in-game gems for real money and spend that on stuff (like inventory upgrades). I can't remember what the costs of the original game were. But, with how they have the game set up, you definitely can "try before you buy".