Use it forever.
What to expect depends partly on your particular circumtances. Like how old you are, and how experienced you are.
The results are extremely modest in the short term. IMO, as someone who is already pretty lean, somewhat muscular, and sort of young.
Good results are seen using the saturation dose multiple times per day. Best results are seen combinging it with CJC 1295 w/ no DAC.
A valid alternative to hGH? Depends how much hGH youre comparing it to.
One of the main reasons people choose these peptides over GH is the price difference.