Well, half of that stuff here is typical lead singer stuff like choosing keys. As the singer, she is the one that is most limited in that her voice type (tonal quality) is fixed and range is limited (some days limited more than others). As an instrumentalist, you have greater flexibility with range and whatnot. So as the singer, you need to cater to her voice and range. That includes key and song choice. Have you considered whether the songs you suggest are suitable to her voice? Is the key suits be to her range? It's really all about her. Just the way it works.

There is also nothing wrong with changing the chord progressions of songs. Reharmonization is very common in music. Sometimes two different recordings of songs are completely different in terms of chord progression. As a musician you are never really obligated to stick 100% to the original progression unless you're doing like a wedding cover band where the songs are expected to sound as close as possible to the original.

It really doesn't sound like there is anything wrong with what she is doing. However it seems like there are issues with the way she is going about it. Have you tried communicating with her? I mean actually letting her know how you feel. If you don't firmly tell her that you aren't happy with the song choice or whatever, how are you sure that she even knows that you have a problem?
There's no such thing; there never was. Where I am going you cannot follow me now.
so are you a band or are you her employee
modes are a social construct
Sorry, you are being unreasonable (and channeling the stereotype lazy bassist).

Complaints 1 and 2 suggest you haven't learned your proper role as the bassist.
Complaints 3 and 4 suggest you haven't learned your requirements as a bassist.

You should be grateful that she is providing an environment where you can learn.
Shake it off and resolve to learn the role and learn the requirements to play better.
Quote by reverb66
I'm pretty sure the Bible requires that you play through a tube amp in Texas.
I like Hail's comment. It doesn't sound like a band or duo. It sounds like a single with bass accompaniment. You should just talk it out and tell her how you feel. Be nice and to the point. If that's how she sees your roll and you don't want to be in that position,  you might consider moving on (but get something else lined up first). 
Yes I am guitarded also, nice to meet you.
Last edited by Rickholly74 at Jun 21, 2017,
Well,  you are the bassist, and that's a traditional accompanist role. It sounds like she should be providing charts or recordings of her arrangements, but I do think you should be deferring to her in this kind of situation.

If you want a co-equal creative role, you have to bring creative material. Song suggestions and criticisms aren't really adding anything. Come up with your own arrangements and show them to her. She's coming up with her own arrangements for a reason, I'm sure, and it's just as much a pain for her to make changes as it is for you.

In either case, I agree you need to communicate better with each other and clarify your role as either partner or accompanist.

edit: there is a lot of creativity to be found in accompanist roles, especially if you're coming up with your own arrangements. If you take an active interest in the music, there's a lot of space to explore. Get recordings of her arrangements you can jam with and come up with parts you actually like. You'll both have a lot more fun when your roles and contributions are complementary rather than competitive. 
Last edited by cdgraves at Jun 21, 2017,

Even instruments like basses are somewhat limited in their range.

Yes, but pointing out the obvious:

1) you can change tuning of a bass to change its range; she can't do that with her voice
2) you can buy different basses for other tunings; she can't do that, unless you count things like autotune.

As for the rest, no, she doesn't seem to be treating you as one half of a co-equal duo. Y'all need to talk.
Sturgeon's 2nd Law, a.k.a. Sturgeon's Revelation: “Ninety percent of everything is crap.”

Why, yes, I am a lawyer- thanks for asking!

Log off and play yer guitar!

Strap on, tune up, rock out!