however, inexpensive folding bikes have cheap parts and are more frequently made using automated processes and with the cheapest labor imaginable. that's why you can buy a shiny new one for less than 400 dollars. they are assembled hurriedly using pneumatic tools and the parts that you as a rider rely on most are often under-greased and over-tightened. but, that's also why, after riding the bike only a few times, you begin to notice problems and start contemplating upgrades.
once this process begins, you are now throwing good money after bad. unless you are mechanically inclined and have bike tools, you will have to pay someone to make the changes you desire. also, consider that most likely you will be paying retail for the parts you add to this bike. very quickly, you will find that you have arrived at the 600 dollar price point for a bike that began to depreciate the minute you opened the box.
for near the same expenditure, you can find great deals on used bikes that come with very good quality components as stock. consider that a higher-end used bike will likely have been properly cared for as it was expensive for the owner and has probably been under-utilized and that is why it is being sold. that's "value for money". the caveat for buying a used bike is that it takes patience and research. but, probably not much more time that you spent contemplating whether or not to buy the bike you currently have.
as you mentioned in a previous post, you don't exactly have disposable income at this time in your life to pour into a pet bike project. this is why i say upgrading is not worth it. my advice would be to ride the bike as is and take note of the things you don't like about it and keep that list in mind when next you shop for a bike. also, if it really isn't meeting your needs, sell it sooner than later.
regarding cplager's recumbent conversion origami, i'm pretty sure i expressed to him previously that it is super cool conversion and i think he did an awesome job on it. for purposes of this conversation, just consider that he is an older guy with an established career and probably has a few bikes and some disposable income to use to play around with his hobby.