Hello and welcome.
-In your opinion, ....................
You posted many questions, I try to answer you all.
I built my Bot myself for many reasons, mainly for a versatility to adapt it to my strategies and needs. I have no direct experience with other online bots or other open sources you mentioned.
I worked many days, occasionally for a few hours in my spare time after work. Today I am operating live with real money after having tested it on testnet for many days.
The most complex part is certainly the construction of the bot, if you have computer skills it is certainly a complex but not impossible job. There are 1000 situations that you must foresee in order not to find your bill at ZERO, but it is a job that I have done with pleasure since it is my passion. If you opt for something ready you will have to adapt to what they offer you, therefore I preferred to do it myself starting from scratch so as to have no development limit.
It is possible to lose everything, and it can happen for a thousand reasons, both in terms of strategy and techniques.
How much profit you can expect essentially depends on the strategy. You will hardly find the winning strategies publicly, you will have to develop it with your trading ideas. A strategy to work must be functional in the long term, in various market phases (uptrend, downtrend, lateral), and you have to calculate it net of the fees that will steal most of your earnings. I personally have two strategies, one more "reliable" in the long term, and one more push.
A backtest is fundamental, the longer the test period the more reliable the future result is, but it has no certainty that what has gone well in the past will go well in the future.
The choice of the pair and the currency (you speak of USD) is a personal choice and certainly also affects the results. I have chosen to accumulate BTC, therefore my strategy is centered on the accumulation of BTC.
My advice is to develop your idea of automatic tradin in stages:
- which strategy I want to apply
- strategy backtest (has it worked in the past?)
- preparation and execution of the bot under test
- live with small sums
- live
I'm currently around 7/10% monthly on the "less risky" strategy and around 35% monthly on the "very risky" strategy, but I repeat, it has been a rather long and complex job in every respect.
If you think you can find a website or ready-made software where you put money, click and make money, I wouldn't want to disappoint you but I think it's really very difficult.
I wish you luck in your adventure