I'm not entirely certain that the soft-top will be adequate during the winters.
Don't be worried. Also - don't listen to any old farts telling you about how much their MGB used to leak in the winter. An MX5 with a properly functioning soft top is 100% watertight. Even if your softtop was absolutely shagged, I'd still recommend you sell the hardtop, and put the money towards a gorgeous new mohair roof.
Both my cars have lived outside through very cold winters, and its never a problem. Even with a foot of snow on the roof there's been no issues due to cold/rain/snow.
Honestly - I speak from experience - All a hardtop does is be a source for cursing when your away from home, its a cold crisp winters day, and the suns out.
A good hood is warm, waterproof, and goes down anytime, in 10 seconds flat!
I have absolutely no experience or knowledge of how to mend/improve things on cars, I wouldn't even know where to start with that little list of small tasks and have absolutely no knowledge of what (if any) tools would be required for them.
Well, you've chosen the perfect car. They are very simple to work on, when compared with many other types of cars. Most things are very well designed, accessible, and sensible.
Here's a job you can do that's easy - rod your drain holes. Ideal to do tomorrow while your having a cleaning session on the car.
When water runs off the soft top it runs into a Rain rail - this runs around the curved rear deck area under your back window. The water then drains into two drain holes, where it passes THROUGH the car, and exits through two little drain tubes tucked up underneath the chassis of the car in front of the rear wheels. Naturally, lots of dirt, leaves, muck etc also gets stuck down the sides of the roof, blocking the holes. Once these holes are blocked, water can back up and ends up all over, usually causing the rear deck carpet to be wet and soggy, getting into your interior, and getting all sorts of places it shouldn't.
This dampness is the main cause of people complaining of soggy MX-5's, and also cars that steam up or never demist in the winter.
The holes simply need unblocking every so often. You need to use something long and flexible. A long bit of stiff cable, one of those very long tube cleaning brushes, something along those lines. I uses a bit of stiff Plastic Vacuum tubing from the garage.
Remove your hardtop ( and sell it
) and look down the side of the hood, behind the seatbelt towers.
You can see the car in that pic has a little bit of muck in that area. You might need to move the carpet about to see the holes - they are in there.
Using your long tool clean out the drain tubes. If its not been done often, you may find there's all sorts of gooey mess in there.
you can check they are unblocked by pouring water down the holes. You should see a steam of water coming out from under the car, in front of the rear wheels.
Its an easy job, costs nowt, but is very important. Anyone 'enthusiastic' about their MX-5 will be aware of this.
Done that - congratulations. You just bonded with your car
If you haven't already, even if you decide your keeping the hardtop for now, I'd still recommend removing it and making sure the hood goes up and down properly, and is in good condition. I've seen a number of cars (My original MK1 included) where the previous owner had left the hardtop on for years and hood itself had actually suffered and was faded on the inside surface and creased badly.
RE tyres. What size wheels do you have? MX'5s being light, and 'sporty' are very sensitive to the types of tyres used. Having a pair of cheap budget tyres on the rear is not a good idea at all.
At the very least, I'd suggest the rears should be replaced. Ideally all 4 though. Don't worry about expensive 'premium' tyres - There's lots of midrange brands that are going to be infinitely better, Toyo, Hankook, Vredestein, Kuhmo, etc etc.
If you have 15" wheels then Toyo T1's or Uniroyal Rainsports are the current best value buys, and you could get a pair fitted for less than £100. In fact if your smart or know a friendly fitter you could get all 4 for about £140 fitted.
The tyres make a HUGE difference to the handling and control of the car. Also bear in mind tyre pressures, which again have a far more marked affect than on larger duller cars. Standard pressure is around 26-27psi all round, so an awful lot of cars actually have OVER inflated tyres.
Get some more pics tomorrow, and if theres anything you want to question post it up! I'm on holiday at the moment so I'm also spending a few days working on my car you see, so I'm in that kind of mood!