Playing on just 1 site is fine and if your happy I would not worry about getting a 2nd one. If you are multi tabling and need more games to play then you should start looking for another site. Before black Friday I played 98% of my games on 1 site. If they were to be allowed again in my country i would go back to them in a second and probably play most of my game there again.
As for more sites it may not go as planned if you find others. .
My favorite site I play the least on at this time, why? They dont have the games I can play at work anymore. In the last year all the games I played were taken away for other games. Now to play i need to take time away from my kids "NOT HAPPENING" or play games i would rather not play with hours of late registration. Sorry, I have a job to go to in the morning and cant do those. If they just left the one turbo on I would play almost every night.
In last few months I have barley played on this site.
My 2nd favorite site, I could play every day on but dont, why? This site has buy ins that is a bit more that I have been able to properly bankroll management play. The time I play is during peek time and I cant afford there games. Game they have a hour /hour and 1/2 before and after the time I could play would be nice but them I need to take from my kids or not get a good nights sleep. Thankfully I have won enough to now play in 1 tournament during there peek time and will be starting to play there more. Just wish the would make it a bit nicer for smaller players at peek time.
My 3rd site have games I would love to play when I could play. The buy ins are perfect but we never play there 5 days a week. why? Many tournament have 4 hours of late registration and all pretty much and re buys. Umm sorry guys, I am going to be before the late registration is over. The re buys all are all in fest early on on the smaller stakes so I stay away from them. I would play them for fun and not worry but the all ins are no fun. Not just going to play higher stakes for fun so I dont play at all during the week.
Would make recommendations but dont know were your from. You may not be able to play on site I play and
visa-versa.