Space is as valuable as notes.
Agreed! I think that for classic country tunes the whole ensemble needs to have a lot of restraint and work together to ensure that the whole arrangement has a lot of space and clarity. The vocals and the lead instrumentation needs to be able to push through to the forefront - a big and cluttered arrangement isn't going to let that happen.
Also, get an upright if you want to play classic country. The big thump with a quick decay you get from an upright works well for country bass lines. Also, I my experience folk musicians and retro purists of all varieties hear with their eyes as much as their ears and sometimes you'll get the call just because you have the upright. It's not too daunting to build up the muscle memory needed for the first handful of positions and it's really a blast to play.
Here's a shot of me last year, bad technique and all!