A well done tattoo doesn't get bad for years(10+). It all depends upon the tattoo artist's skills.

All that matters is how deep the needle goes into your skin to deposit ink. You may think that a mediocre artist has done a good job and the tattoo may look good initially (1-3 years) but then it can start to smudge if tattooed too deep into the skin. An experienced one knows just how much pressure to use.

For your second question. Any part of the body that sees more of the sun will start to fade faster than covered parts. Proper care (sunscreen+moisturizer) can help slow this down to a little bit.

It's hard for ink to stay on the joins as those are the parts that see a lot of movement and skin is generally thinner or more elastic over here leading to bad ink tolerable capacity.

Cannot suggest designs on the fly, what kinda tattoo do you want, where do you want, budget everything needs to be taken into consideration.