Trading altcoins is a good way to build up capital but it goes hand in hand with the following: 'always use money you can afford to lose'. I think you should start with doing research. There are a couple good videos on YouTube that will get you started.
I would recommend using poloniex for trading your altcoin simply because they have the largest amount of volume.
To answer your fourth question I wouldn't recommend getting involved with bots right of the bat. Try things out and make sure you know what you're doing before you get things automated.
I can't really put a number on the risk factor simply because there are 1000s of altcoin out there. Just make sure you avoid pumps and dumps some coins tend to explode today for instance and get dumped the next day.
So my advice in short. Learn it. Understand it. Believe it. Trade it.
Sound advice right there..I started on Bittrex and found it better to use than Poloniex...but everyone will have their own preferences. Key bit of advice is only trade with what you can afford to lose.