About the demo, I think the best loadout is the normal one.
The SR is only for traps which most of the times get predicted or airblasted by players plus you must be there all the times.
The nade launcher is regular of course. Now the Bottle, has an excessive amount of high crit ratio. The eylander has no such a thing and the bottle can be a powerful ally(yeah HeavyTank, remember when you crafted your axe and we fought and my bottle(pain train that time) beat you twice?)
The targe n slash tactic has reason but you have a high risk of failing your target or just getting too deep into enemy territory without escaping.
The targe n chop tactic is completely useless because, well the targe helps the demo get kills with the fail-o-lander to get speed and hp bonuses BUT the axe doens't offer anything with each kill so if you just want to be an I-rush-al-dat-tiems mellee guy, well it won't help much.
A fertile tactic is the normal loadout but replacing the bottle with the axe because, although the speed it makes you more steady and better to counter close enemies like pyros and spies.
P.S. I do not want to hear any whining about the sticky spam, because whether you like it its a tactic that not only works but wastes your ammo really quick so if you:
1)get killed by it it means you do not know how to walk backwards.
2)whine because you cannot do it learn how, it will improve your demo playing.
A tiny example is that before the normal loadout, I was a demo knight and from the demo-sol update till last christmass I had 200000 blast damage, now I have around 590000.