...to put the song in?

Either by changing the tuning of the guitar, re-positioning chord structure, or using a capo, it seems like there are at times endless possibilities. I often times get stuck between 2 (and sometimes 3) different choices for which tuning or key to use.

And the more I listen to the song or play the song in those respective keys, the more my brain seems to become desensitized from hearing the song so much and I have even harder time deciding.

I like to ask musically-oriented friends and family their opinions, and sometimes I get a rather consistent answer. But other times I get mixed opinion and am just even more confused.

I like the idea of picking the perfect key for a song (and most of my stuff is instrumental, so having to cope with a vocalist's range isn't an issue).
I usually keep things in the key I write them in, but when performing sometimes I capo it, or tune down to change the mood a bit.
My voice is suited best for Eb tuning, so I often tune to that. Songs are often in the key of E major or A minor. I steer away from G major when possible. I also use F#m a lot.

Though I don't perceive keys to have personalities, I consider a progression in Eb to sound different enough in say, B to consider the key carefully. For the most part, I write in E major, and I then tune the guitar to E flat.
they're coming to take me away
The problem is: when writing things utilizing open strings, the key you write something in is always restricted by how the guitar is tuned. So I don't want to be lazy and not experiment with different keys that might sound "better" to me.

Any input about that?
I dont give a shit about what key to use, but what position I like.
Playing in F while the guitar is tuned to e standard without capo is just stupid in my opinion, unless the singer thinks its easier for him.
A semitone difference wouldn't be oticed at all, but if my band would like to write a song in C#, then I wouldn't mind tuning down. Sometimes it can sound better changing tuning, most of the time it's not really neccesary.