Have I done any damage?

[Willie]

PYOOR, re "gearbox drag" see above post! The very first
post in this section was from 'DORIS' who started their car
whilst in reverse without depressing the clutch. That is why we
were discussing it.

[rayofleamington]

I still move it to be out of gear first.....

On a moggy there's nearly a 100% guarantee that this will put it in neutral.
On many FWD cars there is no guarantee at all! The shift lever is connected with linkages and plastic ball joints - there are hundreds if not thousands of recorded cases of the joints coming undone so the driver could think they are in neutral when they are not (My montego gear linkage came off quite a few times until I put a bolt through the plastic ball joints)
You just have to imagine the scenario of a child walking between the car and the garage wall whilst you are trying to start the car to see why most vehicle manufacturers recommend declutching during cranking.
As for starting in gear - that's a bad idea.

[salty_monk]

OR the brakes can cool down (especially with rear discs) shrink, release and the car can roll off

My friend did this is his Golf GTI, parked on the slope outside his girlfriends garage - straight through her old man's garage door made me laugh!!

My montego gear linkage came off quite a few times

Ray, what do you expect, buying a Montego!! (ducks)