Does it make a difference if yeelight is turned off from the switch like a normal light or will it affect it in any way? I was just wondering because I am new to yeelight.
If you turn it off from the switch, you won’t be able to control it from the app until you turn the switch back on. Best thing to do is to leave the yeelight switch ON and do all the controlling within the phone app
But will turning it off affect the bulb in any way?
Also my Alexa is not able to discover the bulbs even though I am on the Singapore server.
No it shouldn’t. It will reconnect to WiFi when you switch it back on. There’s no reason why it should harm your light. Just don’t switch it on and off 5 times consecutively because that resets the bulb. As for your Alexa question, I’m not an expert. Wait for yeelight staff to reply
Thanks
Will the power continue to run if the switch is on and the yeelight is off and would that be expensive like in electricity charges??
Yes, it will consume some electricity… I think I read like 1.5W…
is that a lot, and also my Alexa dot is not discovering any yeelight devices, I am not the Singapore server.
Well, it is all relative… normal classic bulb is consuming like 100W… So I have like 11 devices (including bulbs, ceiling light, strip etc) it is like 11x1.5 that is 16.5W… it is still a LOT less than if you had 1 such bulb on all the time 
And it is almost nothing compared to really big consumers like washing machine or dish washer, water heater etc, etc…
Also my Alexa dot is not discovering my bulbs and I am on Singapore server. What do I do??