I'm a wind musician, who also plays some piano and a leetle bit of classical guitar.
I'm my own personal argument to anecdata.
When teaching beginners, I've had the greatest success when I get their fingers moving first. I teach music notation 2nd. That way, my students don't freak out when they see the 'fast' notes, or the 'high' notes. Because they start out pleased that they know all the fingerings within one lesson, their excitement lasts longer.
When I started out as an elementary school kid, we were only taught a new fingering when we were taught a new printed note. Most of my cohort then confused their ability to sight read with their ability to move their fingers. "OMG! Eighth notes are so hard!"
Granted, that may be a required teaching method when dealing with 30 kids on 5 different instruments that are supposed to play together.
1) If you start to lose drive, (happens to most people), just plan to pluck a few notes on the guitar every day. Five minutes is fine. This was incredibly helpful to me when I wanted to be a better musician. I'd not be in the mood to play, and wind up playing for an hour. Other times, just 15 minutes. Either way, I didn't beat myself up, and became a much better musician.
2) Get a lesson or two from a decent teacher~they can teach you better ways to hold your guitar so that you play better AND prevent long term damage to your tendons.
3) Notation: Ultimately, knowing how to read all notation--chord charts notation, etc is integral to being a well rounded musician; After all, the difference between a drummer and a percussionist is the latter's ability to read music. HOWEVER, the most important thing of all is that you Play.
4) As my teacher used to say, "Practice makes Permanent." Anything you do repeatedly will get locked into your muscle memory, good and bad.
Good Luck and Good Skill!