Hello Karl,
at Stridaforum
Most likely they required infos are present already - just to find it may be tricky, I do know that very well 
a.
Yes indeed, there may occure problems - with the standard, short handlebars.
But not with either the bent steering kit or the moustache bars:
https://stridacanada.ca/product/strida-bent-handle-bar-kit/
https://stridacanada.ca/product/strida-m-style-handle-bar-set/
b.
That is solely your decision, depending on many very personal attributes.
Besides of the financial aspect, the local road situation (hills?) and other logical considerations Iād recommend that you ask yourself questions like these:
- Can I do simple maintenance by myself?
- If not, as there is no Strida dealer near - is there another experienced and nice bike workshop within reach who could assist me?
- Am I willing and able to install, for example, a kit of wider steering bars by myself?
Most likely you mean the development and the EVO drive info is right here:
Re: Gear ratios information about different models of Strida
Hint: To find more about the EVO drive please use the forum search and keyword āSturmey Archer KS3ā, too 
Kind regards,
Chris