The wall oven door wont shut at the top by about approx 1/2 inch. I took off the door a few times but couldnt work out how to adjust it.

Try this link ... owners manual ... go to page 15

https://www.searspartsdirect.com/partsdirect/user-manuals/gsc309pvs02-whirlpool-parts-manual

It shows how to remove the door and talks about how to release the latches.
It sounds like whomever cleaned it ... may have removed the door and not reinstalled it correctly??
Helpful?

Unlikely there would be no air spilling through the door seal because it is an oven and not a watertight compartment. An oven door seal needs to be hard wearing and able to withstand high temperatures and hot grease which limits the materials used, that and the fact few domestic oven doors actually latch these days but are held closed by springs meaning the pressure against the seal is relatively light which means the door, the shut and the seal must be manufactured to a high degree of accuracy and properly adjusted.

If the amount or air leakage is excessive perhaps the door could be adjusted or the seal replaced. Try asking around to find someone with a similar oven so you can compare...

you have a couple of hinges you have to pull out at about 45 degrees then slide door down on them and shut door

Some are made where you just pull up on it and some you actually have to remove the bolts and stuff

The door is probably out of adjustment. Remove it from the power source.
Remove the top cover and examine the door catch housing. There usually are a couple of screws clamping this in place, loosen the screws, shut the door and tighten the screws.
Finaly, check the hinge for clearance, (No more than 1/10th inch), and adjust as needed.
Hope that helps.

Remember that there is a little play in the hinges, even new ones, enough that just a slight degree of play at the hinge axis will result in several fractions of an inch movement at the latching end of the door. The key here (assuming the lower hinge is still mounted at factory height with respect to latch) is to adjust the angle of the hinge's axis such that the latching mechanism is 1/2 inch higher than the stiker plate BEFORE tightening down the hinge's mounting bolts, then when you remove your support holding up the latch end of the door it should sag back down approx 1/2 inch and line up perfectly with the latch plate. I used to do this on an old '79 Monte Carlo I used to have and even being the smallest of the Monte's, it still had fairly long, heavy doors for back then even and could get the doors to shut/latch perfectly. I own a VUE now-a-days and its door's are featherweights by comparison so they should be fairly easy to adjust and you shouldn't have to tighten the @#$% out of the mounting bolts during the adjustment, just make sure you tighten them good when the alignment turns out correct upon final inspection.
If your adjustment sags again after shutting the door a few times, then you didn't tighten down the hinge mounting bolts enough and will have to go through the adjust procedure again making sure to tighten things up better the 2nd time around.

some units will need to be adjusted if you live in a high altitude above 3000ft.

This sounds like a loose connection (solder joint) on the main control board. I had one that had a similar problem. checked the price of a control board $350. I took the control panel off, took the board apart and found a loose connection on one of the relays. resoldered the bad connection. oven works fine now.

the oven door lock assembly has locked its self in to clean you can find the door lock assembly at the top of the oven where the door shuts sometimes if you push on the locking hook this will solve the problem

Big oops, Millwood. Shut power to the unit immediately and wait a day or more for it to dry out. If it works then, fine. If not, you've got a learning experience installing a new pad.