Hi,
I am going through a similar process I don't think I will end up with the same choice but its the thought process that counts. I would ignore some of the partisan discussion and concentrate on what you want. The impression I get is that you've not quite made up your mind on what you want to do with this bike. I suspect when you get it you will use it for things you never anticipated.
The first comment I would make is don't paint yourself into a corner, my greatest fear. If you spend 2k on a bike its got to do what you want not what someone tells you want (especially dealers). If you don't know that for sure don't buy until you do. It has been said that you should try bikes out that's sound advice test as many as you can.
Being small you might find difficulty in getting a bike that fits. Small bikes can be hard to come by e bikes are no exception some makes may be too big for you. You actually need to go to the shop to try the fit in my opinion,the brochure is only a guide in this respect. This is even more important if the bike has a cross bar.
There are various types of drive to add to the confusion which I wont go into but there are various pros and cons of different manufacturers and drive systems in terms of cost, reliability and life span. I would check the forums for this, It's a major topic of discussion and its not obvious on face value what the answer is. Sometimes the most expensive is not the most economical long lived or reliable.
As for how the different types feel only riding bikes will help you there. Generally the received wisdom is mid drive better to ride but less reliable, hub drive more reliable(much) but not so good on hills. This is an over simplification and there are exceptions to the rules.
It is also important to try bikes to asses the resistance with power off, most hub drives have negligible (geared type only) some mid types do some don't. You need to try I have found some that do and some that don't in one case the same manufacturer, same type and in the same shop one that had none and one that had a noticeable resistance.
It may be that the best type of bike is an all rounder as you suggest covering as many bases as possible. Look for a hybrid type that can take racks, mudguard, accessories and different tyre types for different uses. I say can take not must fit that's up to you the only thing that is important is that there is an option to do so if you think that is the way to go at a later stage.
I saw a Boardman bike being mentioned as an option. That one I fancied but its really quite limited,this is an example of how you can go down a blind alley. I like the bike(a lot) but it would not be suitable for what I want(done this a few times). The battery in particular was VERY small most bikes worth considering will have 400wh or 500wh. Weight is the focus or possibly keeping the price down as the battery is normally an expensive component. Goto the Bosch on line range calculator and you will see where the compromise is. Its light weight but weight on an e bike this only makes a marginal difference, the main advantage is lifting the bike onto trains and up stairs (often very important). Light weight will not compensate for a small battery youll have to do that by pedalling harder.
The next thing I would say that on the forums most contributors are enthusiasts. Many are heavily into modifying, repairing and building e bikes
Although having said that, it occurs to me that there is a localish shop which might be able to help me with the sourcing, hmm...
Your on the right track, if you are not into that sort of thing as you have said find a local supplier and more importantly someone who can work on the electrics, preferably the dealer as well.
I would avoid any thoughts about conversion unless you are confident you can maintain the electrical parts of the bike or can find a willing installer and repair shop locally. I haven't tried but there are reports on the forums this is difficult for e bikes, something you need to check out before you commit. I would also avoid any make of bike that cant be serviced locally as well.
You are left with bikes or conversions that can be sourced or done in locations that can be reached without too much issue. Start from there. Look for something that's versatile, that you like, will do what you want, can get serviced and repaired easily.
You need to go shopping good luck and hope you find something soon and never take on face value statements like, "these never go wrong", check the internet, in my case I found out oh yes they did very much so. That was on a 2k bike with a leading mid motor manufacturer.