Can't comment on the Z4 but my 2008 Civic Type R was much less involving, the engine was better than that in the MX5, gearbox about the same, both fantastic, but the chassis on the Civic was just dull, felt heavy, and the (electric) power steering lacked feel.
The MX5 is just more balanced, more feelsome and just more enjoyable, more of a proper sports car than just a hatchback with a grunty engine and hard suspension. It lacks refinement even compared to the Type R though, a car reknowned for hard suspension and short gearing.
Its the most fun car I have had (I discount the S2000 from this as my ownership was so short).
My usage profile is this - I do lots of short journeys too/from work or places around town (average well less than 10 miles/day), and then my fairly infrequent longer trips tend to be for recreation anyway, so I'm not time pressured and can take detours to enjoy the back roads. For me its worth the trade off of refinement, to have something fun for those occasional longer trips. Buts its not a great car for lots of motorway mileage or many long trips....if you don't do many miles though, and want something fun for the occasional long trip, pound for pound its a good option with very reasonable running costs. Still good enough as a daily, the Mk3, comfy and nice enough inside in a well specced one - good stereo, heated leather, and a good heater make it a nice place to sit for shorter journeys even in winter with the roof up. I honestly think you'd cope well enough with one as a 'daily driver', especially with a hardtop, coming from a 95 Almera
Going back to your question about Mk2s and rust, its an odd one. The most 'fatal' rust (that which means its not cost effective to repair and leads to the car getting scrapped) on the Mk2s is not sills or arches as on the Mk1, its the front chassis legs (the bits that the engine is hung between and the front suspension bolts up to).
Mazda did not corrosion proof the front chassis legs very well on the Mk2 and they suffer chronic rust from the inside out. The strangeness is that the later Mk2 facelift (2002 on, often called a Mk2.5) cars suffer worse than the 1998 to 2001 Mk2. The rust is not often visible but is an MOT failure as its structural. For any prospective Mk2 purchase I'd insist on having the undertray taken off and have it properly inspected on ramps, to ensure its solid enough. The problem is bad enough that MOT testing stations are told specifically to check those cars. Plenty of Mk2 owners have been burned, buying a car that appears sound on the outside, only to find the structure underneath is badly corroded. Cost of repair is often prohibitive as its an engine out job to fix and the repair parts from Mazda are about £400 per side too, seriously pricey when the cars fetch £2-3k.
Spending just a grand on an MX5 is tricky, some real rotters around for that money, I'd avoid Mk2s at that price, and look at Mk1s only. At that price its likely all will need some mechanical work and ongoing maintenance to keep going, and many will be rusty.
My thoughts on doing this are this - if you are handy with a spanner and want something to tinker with as a toy, then fine, go for it, its fine if its a hobby car. But you could still spend several hundred on maintaining one then have it fail its MOT and need scrapping without spending proper money on rust repairs. And if a £1k purchase is truly 'disposable' to you....then you probably have enough money floating around to sensibly buy and run a nicer one anyway as a daily driver.