Need Help With 2 Things

how can i make the hero lvl limit at 99

and

how do i make a slot in my map always computer and not able to change from computer to open (or closed or anything else)

To change the maximum Hero level, go into the Gameplay Constants option (under Advanced on th toolbar on the top of the World Editor) and then enter the desired value under Hero Maximum Level. Make sure the 'Use Custom Gameplay Constants' (at the top of the gameplay constants screen) is checked, or else it won't let you change anything.

to prevent the user from changing the computer slot into anything else
go to Forces tab from Scenario properties and enable custom forces and
fixed player settings.