i need to ask abt sealer for ceiling.. be it plaster / not plaster ceiling...

some guy intro to me this san cora sealer says that its not bad...

and also i need some advise... pls help...

1) sealer for wall and ceiling can use the same type sealer? what is the better and value for money i.e not too expensive but average still ok

2) what about sealer for main gate... cox its a new hse and i need to repaint the whole hse so i will have to repaint the gate to suit the wall colour.

and also, what is the difference btween satin glo and 3 in 1 paints for nippon?? i can see is price only lolz...

can anyone tell me if i can mix nippon odourless air care with some water cox its so thick and difficult to paint???