Advice on migrating/upgrading

[mohsart]

For a couple of reasons I will move to a new host shortly and I haven't yet decided exactly how I want things.

 

I have three shops, where only one is completely live, one is up and running but barely started and the third is currently just a test.

My domain is mohsart.se and in the root I have the live shop, 1.4.3.

In mohsart.se/handkraft I have the just started one, 1.5.2 and in mohsart.se/tea I have the test shop.

I will most likely upgrade all shops to 1.5, the bugs seems to be possible for me to handle, and hopefully 1.5.3 will be out soon and prove to be a bit more stable than 1.5.2...

 

First of all, I'd like some advice regarding multishop, obviously I could put all three shops in the same installation, but I'm not entirely sure this is the best approach.

I know next to nothing about multishop, but if I cannot have different themes, modules and make code modifications for one shop that won't affect the others, perhaps it's a bad idea...

Are there disadvantages, other than future upgradings, to make three separate installations?

 

Then, structure: I'm thinking of using three subdomains, i.e. games.mohsart.se, handkraft.mohsart.se and tea.mohsart.se, where I suppose each subdomain will in reality be a folder in the root.

 

And lastly, for the actual process: Is it best to copy everything to the new host and then upgrade, or is it better to make a fresh install and then import a dump from the database?

Will a 1.5 installation be able to import a db dump from 1.4?

Will a multistore installation be able to import three db dumps?

 

Other advice, recommendations etc also preciated :-)

 

/Mats