I've seen some photo's taken with 100mm refractors @20s subs and they seem to show quite good detail in a 20-30 frame stack. Would reducing the aperture down to 80mm, or even a 50mm finder , increase the length of of the exposures by much and make the size of the image scale appear very small?
I'd like to try out a cheap set up to begin with to get some idea of the different variables that might effect final images.
I can find no reference to what sort of computing power is necessary to run the software: is Ram important, or is the data written directly onto the hard drive?
No, the large-scale details shown in most EAA screenshots are far below the reoslving power of even small telescopes; the lenght of exposure depends on the camera's specs and telescope's focal ratio, while the image scale depends on the sampling (id est, how much of "sky" is seen by each pixel).
Being sampling a function of focal lenght and pixel size according to the formula (mm pixel size/ mm focal lenght)x206265, and the field of view the product of sampling and pixel number (width, height or diagonal), you may check easily if a setup is suited to your aims.
Softwares like Firecapture (the one I use for planetary AP, and the same tried when made my mind about EAA) works on very lowly PC (I used a really low-end 12" laptop with a 2.16GHz N2840 celeron and 2GB ram ), both for the capture and for the live-stacking.
I eventually drop my interest in EAA (despite the fact that could have upgraded my mount to use its HC as screen and to control a videocamera, without rsorting to the laptop), so others could give you better advices, but still find a bit awkward the choice of the LodestarX2: it is for sure one of the best pick for guiding, but it is also a rather specialized device and the mix of huge pixels and small sensor would force a very peculiar behaviour upon your setup