Brokers can sometimes archive your account due to inactivity. But it is quite easy to restore them with a simple support message. Never had an issue with that.Demo accounts are valid indefinitely. Accounts of this type will remain active as long as you log in on the trading platform at least once every 10 days, i.e. you connect or reconnect your account to the server at least once every 10 days.
We cannot deny the abilities of traders however in my opinion new traders should trade demo for at least a minimum of six months before moving to trade with live funds.Well it all depends on abilities of the trader, for some 1 week is enough, for others 2-3 months is needed, but I guess the average is 1 month