i think i can mark this as solved, solution: Pull my head out of my...
took it back to the shop and he explained that he had it set up correctly, that it was booting into the ssd, which he proved to himself by pulling out the hdd from the dvd adaptor. so he recloned it and now everything seems to be working faster. i also tested without the old hdd and it does indeed load correctly. i guess the problem was that it was loading so slowly. i took the old hdd out of the dvd slot and replaced it with a new 2gig transcend, putting the hdd into the transcend box it came with. i then booted the old hdd through usb3, counting 25 seconds for it to load. nice to have an external operating system that i can plug into any computer. but when i restarted and booted from the ssd, it took 96 seconds for the OS to load. any suggestions how to fix? otherwise it is working noticeably faster once i'm in.

thanks for all the useful advice above, which i'll store in my notes for future use.

okay, everything fine now. will mark as solved cause there are a lot of interesting points here that can help others.
what concerns the very slow loading of the system at startup, i also fixed that once i got the swap drive set up. thanks a lot for all your help!