3 days now no sighn of germination?

Not sure how long it will take but if I was to inoculate would it end up germinate at the end?

Just give it time... you can't rush nature.

Patients is a virtue cannabis seeds take longer to germinate lol. A warm environment helps if it is only like 70 degrees it will take longer but give it a week you should see some fungi growth they have no choice but to eat as long as you inoculated properly. Like if you injected the spores while the jars were still hot you would have killed them. But don't worry just because the syringe looks like it's full of just water don't mean a thing but they don't use as much as my homemade spore syringes but mostly I just use spawn but I grow a few types of mushrooms.

It is difficult to see early germination especially on non agar substrate. Relax. As tamper said, if you didn't inoculate too hot and if you actually saw even a few specks in your syringe you will surely get something.

I inoculated straight away from sterilize the cakes in pot and lid meth. Would it have killed them?

If you didn't let your jars cool the the chances are yes

Will they grow?

Which setting do I set too on the stove?