1/ If I don't use leverage (i.e. x1) do I risk being liquidated if my trade doesn't go in the right direction?
If it is long position, you may not be liquidated. But if it is a short position, you might be liquidated, especially if trading altcoins that can do 2x within some hours or some days.
2/ If I don't use leverage (i.e. x1) can I keep a BTC contract, how can I do this in the Spot market?
You will be charged or given funding rate fee. This might be a disadvantage. It is better to go for spot trading if you want to go long with 1x. To go short position, you need to use 1x leverage in future trading.