Not sure I understand your questions but I'll take a stab. I suspect the Schwable is similar in size to the mtn bike tire you replaced it with, yes? Most mtn bike tires are at least 2.0 or wider. Most tubes (especially the larger/wider sizes) fit a fairly wide range and it should fit fine.

A bad angle on the valve will eventually cause the rim to wear through it and cause a flat. It's easily adjusted by letting out the air, grabbing the spokes with one hand and the tire with the other and then pulling it in the same direction as the valve is pointing. This will straighten it back to a 90 degree. If it doesn't want to move keep letting air out until it moves. If for some reason it doesn't move, you might have to open (unmount) one side of your tire to get in there and move the tube itself, then close it back up.