Hi Aceman18,
My flight school is pretty decent, we have fixed roster pattens so either 5/2 or 6/3 and we also can do custom rosters if they don't work for you. I am only new to instructing mind you so probably not the best to ask. However, I am a sponsored FI so the company paid to train me up and I have just started flying, I am currently on an upgrade package to get my IRI done as soon as I am experienced enough so maybe 6 months or so and have the option of upgrading to CRI(ME) later down the line if I put in another two years. Can be quite busy as we usually have a lot of students but quite manageable.
You will have between 2 and 4 sorties a day depending on the length of them, if you are instructing a PPL level you will usually have more sorties unless you have two long events, not always time to have a proper lunch break in between flights if it's a good weather day but as the job is salaried you will have other days with very low workload but still get paid so can't complain!
Anyway, I enjoy working for my flight school, it is tough at times but very worth it. I know I will be happy here for several years at least!