Firstly, dont worry about the Accord, once you have the Zed the first thought you give to it will be in about 3 months when you remember you still have it and get round to selling it.
Cant think of any issues with the Zed, if you trawl around the forum there are no major breakdown faults that I can recall.
The mods issue, I guess everyone starts with a stubby aerial etc and is soon into pop chargers zorsts etc. There are plenty of traders on the forum and here the dollar is king, importing parts from the U.S.A is not only a lot cheaper but relatively easy and quick.
Insurance, down to the postcode lottery again Im afraid. As always, shop around. I am a few years older than you and mine came in about £80 p.a more than my Honda Accord.
As for mpg. I drive from home to work on about £65 of petrol, its about 340 miles so not too painful, as ever it depends on whats in front of you.
If you can, get to a meet, apart from the car ( which is bloody awesome) you will soon be caught up in the whole Z thing.
And, if you want to ask any questions, go ahead, the stupid ones will always have been asked before, probably by me.