Leaks and no-spin faults are usually a pump, a bearing or a control board. Three very different price tags, and guessing costs you the wrong one.

A washer that fills and washes but leaves the drum full of water is a drain problem, and the drain pump is the first suspect. Before the pump gets condemned, the filter in front of it gets opened, because on front-load machines it collects coins, hair pins and the occasional sock, and a blocked filter looks exactly like a dead pump.
No spin with an empty drum is a different fault. On front-loaders it is often the door lock assembly, since the machine will not spin unless it is certain the door is latched. On top-loaders it is often the lid switch, the drive belt or the shift actuator.

Open the pump filter, usually behind a small panel at the bottom front, and have a towel ready. Check that the drain hose is not pushed too far down the standpipe, which siphons water back out and mimics a dozen other faults. Run one cycle with nothing in the drum to see whether the noise is the machine or the load.
Yes, quite a lot. Front-loaders fail at the door boot, the door lock and the bearings. Top-loaders fail at the lid switch, the shift actuator and the drive system. The diagnosis path is different from the first minute.
Sometimes. Shipping bolts left in place, uneven feet and worn shock absorbers all cause it, and only the last one is a parts job.