Wow your hair is so long, especially when straight. I often straighten mine after washing and let it go into waves that curl at the ends. On the third day it looks great. I only wash my hair about once a week (something which alarms and disgusts straight haired people! They don't get the whole it doesn't get greasy thing... lol)
I use Frizz Ease Thermal protection serum at the mo but do you recommend an alternative? It's so important to protect hair from heat. Straightening seemed like a really big deal to me before I started doing it. Now I love having options and it's easier to maintain until the next wash.
Straightening is fine as long as it's not too often and you always use protection...! I'd never do it daily, hair would be wrecked after a while!