It's fairly safe if you operate in a well ventilated environment, have fail-safes in your still in case there is a pressure build up, and use electric elements instead of gas.
Plenty of people use gas, but I don't see why given the increased risk and cost.
For gin you need to make or buy neutral spirit first. Buying it is ideal as larger providers can make it cheaper and cleaner than you, but needs a license so you won't do this while you're developing a product.
Then you will likely use a pot still to make your final product. You can use the same equipment to do both processes if you have a modular design.
None of the above is set in stone - gin is a bit like jazz and breaking the rules is common.
Capital needed for distillation? Just watch an episode of Moonshiners on Discovery channel and you'll be set. Nothing you couldn't buy at Home Depot or the local hardware store for about $100.