I have a quick question (or two) regarding getting refinancing!

1) Do I have to wait until the end of the term of my mortgage to refi? 

2) How is the equity paid out? ie. Existing mortgage of $350,000 Valuation of $400,000 with LTV of say 70% gives me $35,000 ... is this just processed as a cheque and then the 35k+int gets added on top of my existing 350k?

Thanks! x)