H1b transfer from for profit company to not for profit and back to for profit company

I am currently working for profit company on h1b visa . I have a job offer from not for profit company. I have used 2.5 years of my first term of h1b visa . I want to know if I accept an offer from them (not for profit and non profit are different as per my employer)and transfer my h1b, then how does it affect any future job opportunities in terms of transferring my h1b to Profit organization. For example if I work for 2 years with not for profit org , and if I want to transfer my h1b from them to again a for profit organization , then could I easily do that ? 2 ) Would I be counted under h1b cap again ? 3 ) Since h1b visa could be renewed for total of 6 years before filing green card , then would 2 years at current for profit and 2 years at not for profit would be applied towards 6 years of h1b visa term ? Please help. Looking for suggestions.