The reliable way to hire a tradesperson

Hello, I'm planning to replace my front door and rear french doors. Should I be looking to hire someone who will replace/fit the doors after acquiring the doors myself, or looking at someone who I would also acquire doors from and can measure up in advance?

Hello, im laying 10mm 600x600 quartz tiles on plywood. Im using Ultra Tile Fix Pro Flex S2. Should I replace the water with latex as google AI says or is water ok? Cheers

Ceiling was recently boarded over original lath and plaster. However the plasterboards used are offcuts, ranging from 20x60 to 60x120cm. All screwed into the ceiling joists. Understand it’s not ideal, however we are where we are. What’s the best way forward to reduce future cracks. Would 100mm scrim tape on all joins sufficient? Or getting 1m big scrim sheet and scrim the full ceiling? Any advices appreciate. Thanks