Refinance a loan

[Michelle Pinneo]

First post, I have a few questions

Lets say I purchase a $100,000 multifamily property, and I put $20,000 down. At the end of the year let's say there is about $5,000 paid into the loan from rents and the original $20,000 that I put down so for a total of $25,000 equity. My question is would I be able to pull out the entire $25,000 equity and put it towards a new property? So this is kind of like my $20,000 down payment was only in the house for one year. And if so will a lender let me pull the entire amount of the equity so I'm back to 0 down? Will I get hit with capital gain tax if I refinance in under a year but NOT SELL the property? 

Also wondering when a new property is purchase that already has current tenants, do the tenants have to re-write a lease with me? Can I raise the rent even if the property was rent controlled? And what about their initially paid security deposit to the old owner? Do they need to fight the old owner for their deposit to give the new owner (me) or does the deposit just become my problem when they move out? Any answers will be appreciated. Thanks so much.