Changing your own tyres isn't difficult, you don't even need the tyre changer from Harbour Freight, just the right technique and some tyre irons. The wheels have what is known as drop centre (where the spoke heads are. ) First make sure tyre is loose on rim, no air and bead not stuck anywhere. Start with levers at the valve, press tyre into wheel well opposite ( drop centre) and start persuading tyre it really would like to live somewhere else. Take small 'bites' and work around rim. you may pop a tube or two while practicing, but its still way cheaper than the shop. Put a small amout of air in tube when re-fitting, only enough to hold shape to make sure it doesnt get trapped under bead. fit nut but dont tighten it down, press valve into tyre for extra clearance. ( only up to nut) Start at valve, finish at valve
As for balancing, you only need some way to hold wheel and find heavy spot (which will be at the bottom

) Old swing arm works, either in a vice or couple of cross pieces welded on to hold it upright. take brake plate off rear wheel and take out the spacers when you do front so there is less drak from seals etc. Unless tyre shop does correct dynamic balancing ( difficult with the narrow rims we use) its no different to static balance, just a bit quicker with machine)
PJ