I have a 94 plus 4 also bought from Allon White so likely to be very similar.
As most have advised the tyre pressure is critical, too high and the car will nod. If new tyres have been fitted it is possible that the tyre fitter will be unaware of the low pressure required ,for me it’s 22 to 24 psi,
As for the petrol smell it is very likely that the fuel line rubber connecting tube is perished, it may look ok but if you squeeze it it wlll sweat petrol, this was one of the first faults I found with my car. At this age it is likely other rubber will also require replacing, things such as grommets will often just crumble. Also check for rubber hoses that may be chafing, As it’s the Rover T16 engine it’s likely to leak oil from the rocker box gasket, not serious but messy, fortunately none of these issues are expensive, just annoying that they were not addressed by the previous owner. Stick with it, it’s absolutely worth it.
