pretty much answered above.not having mid control doesn't matter.bite is important to give twang especially in your
low strings, they don't want to sound fat, the definition will be lost with too much bass.
compresser is standard but if your attack is too low your bottom strings lose definition.compreesers are v.good in a live situation to give a boost to solo's but more importantly to fatten the sound and give sustain.the guitar is more 'playable' with a compresser.delay can be a slapback ie. 1 v.quick repeat giving a 'rockabilly' sound, or longer delay settings for filling your sound.don't forget all country isn't manic picking.
i generally use a clean tone but some players like brad paisley use quite a bit of gain.in fact a loud amp gives natural compression and makes a clean tone 'bigger'.
check out doug seven, the most important thing for country is using pentatonics/chromatics in the right way.
oh and single coils, hope this helps