1) No, you don't have to cut your hair! Just add some protein to balance out the moisture. It's easier to correct over-moisturized hair than it is to correct over-proteinized (?) hair.

2) I'm loving All-Nutrient's Proteinizer. It's mostly keratin, and it sprays as a very fine mist so it's easy to control how much you put on. My hair loves protein, so it takes quite a lot of spraying. I've thought about actually opening it and pouring a little out! It smells really good, too.

I've also used Colorful Neutral Protein Filler. It's mostly keratin, too. It's available at Sally's and Amazon, and you can mix it with your gel, conditioner, etc. I don't notice any smell with it, either, so it should play well with your scented products.

Nature's Gate has conditioners with protein in them, too, and you should be able to find them in grocery stores.

Aubrey Organic's GBP conditioner is wonderful for at home protein deep treatments, too.

3) I can't see the photo for some reason, but you can pull out your curl/wave and make your hair more straight if you pull it back all the time. Some of us pull out the curl just by combing or raking our hair when it's wet! I'll leave it to the other curlies as far as whether it can affect your hair in other ways, though.
2b/2c, fine, thick, normal porosity/elasticity

Current routine: co-wash & detangle with AIA Coconut CoWash then RO. Experimenting w/AG re:coil, DCVF & All-Nutrient Hair Proteinizer.
Love: AO GPB, KCCC, PBH Gelatine Goo, ANHP, CNPF
Like: GDL, FSG, honey, HETT, JCNS, DCVF
Hate: glycerin, mineral oil