Well i am new to salt water (haven't started my first tank even, doing research first) but i have a lot of experience with the nitrogen cycle from 2 years in freshwater. So that said with regards to your cycle You should have seen ammonia spike then nitrites spike then nitrate start to climb. Have you tested for nitrites and nitrate? If you see no ammonia, no nitrite and a little/climbing levels of nitrate your cycle is complete. You should change 25% of the water and you can add ONE hardy fish now (what fish idk really as again im a salt newb but im told clowns, damsels and fire-fish are hardy. Dont take my word on that tho! Do some more research or wait for others to chime in). Then feed it sparingly so as to not add to much nutrients to the system to fast, he will look hungry but the little piggies always do even right after they eat! Keep doing weekly (or when nitrates start to get high) water changes and in another week or so if all your perimeters still look good you can add a second fish and so on and so forth. I cannot say however when to add corals but that rock should work fine for them when you do add them. Your PH should also be fine as i am told 7.8-8.3 is good for a salt tank.