Microsoft Contract

I have recieved a 18 months contract BI Engineer position with Microsoft, at Redmond, WA, TC: 100K, YoE: 1.5, Education: MS Analytics. I currently work at Verizon as a contractor. Recently interviewed for Amazon BIE lvl 5, went to onsite but nearly missed it (didn't prepare a lot on Leadership Principles). What should I do. 1. Should I join Microsoft. What's the possibility of contract to hire at Microsoft. I know it depends on teams but want to know what's the usual case, if the performance of the candidate is good. 2. I want to apply again at Amazon as a BIE, in 6 months. Will going to Microsoft and changing companies frequently give a negative impression on resume. 3. Amazon TC was $160K, MS contract is $100K, should I negotiate more ? They started negotiating with $90K. 4. Should I stay at Verizon. Though the work is basic but it falls in line with Amazon BIE. Please help. Thanks