Greetings,
May I endorse Vern's comment about strapping some tools, such as the tyre levers and brake/clutch levers, to the various chassis rails to save weight in the bag.
Out in the countryside a colleague can use their side stand as a bead breaker tool to force the first part of a reluctant tyre off the rim.
If I might suggest a Motion Pro bead buddy (other makes are available) adaptor which really do work well when refitting tyres, plus if changing tyres/tubes at home remember to sprinkle talcum powder around the tube or inside of the tyre to lube and cool the tube in motion. Do not secure the tube to the wheel rim with a locknut so as to allow possible movement should the tyre move on the rim otherwise the tyre can pull the tube and rip the valve body off of the tube.
After fitting a tyre use 'Tippex' to mark the tyre and wheel rim so that in use you can quickly see if they have moved in relation to each other.
I have used the tyre slime to which you make reference to act as an inner lubricant to the tube, at low tyre pressures I think that it helps prevent 'snake bite', punctures but that is just my opinion and others are free to disagree. If you do use such a product then make sure that when you check tyre pressures that the valve is higher then the 9 o'clock position or you will get covered in the stuff
Additional ideas are that some folk after buying a used bike will fit a new clutch and/or throttle cable, leaving the original in place strapped to the new one.
Motion Pro also produce a compact multi tool pack, which I carry and have used to good advantage in the past.
You will pick up lots of ideas by simply looking at other folk's bikes and from talking with members out on a run.
TTFN
Hugh.