Re:
In terms of chainline, you don't have many options other than to run a single ring on the inside of the crank bolt holes. You should aim for the chain to run as straight as possible in relation to the centre of the cassette. Running it in the outer position will almost certainly cause problems.
You can sometimes run a shorter BB to help with the chainline but you need to obviously watch for chainstay clearance.
As an example, I run a 107mm rather than the usual 110mm BB on my 8 speed Stumpjumper to improve chainline. I use a non ramped chainring (no lowered teeth for improved shifting) in the middle ring position and I've also fitted a chainguide to this one.
If you ride mostly on roads and smooth trails then you'll probably get away with no chain guide, inner or outer bashrings.
But any rough sections or pot-holes etc, can cause problems, especially if you use ramped chainrings rather than single speed specific or non ramped rings with taller teeth.
Narrow wide type chainrings are pretty good, but you really need a modern clutch type mech for them to work on rougher off road stuff. Otherwise you still need a chainguide.