Blockchains are INSANELY expensive to secure. You are saving a fortune right now by using a normal database or whatever to record people's balances and do transactions, basically you are doing "off-chain transactions", and that is the way to go for on-site interactions.
Blockchains are really only useful for going off the site to unknown destinations the site does not control and for coming onto the site from who cares where with something the site considers valuable.
Thus the entire insane expense of trying to secure a blockchain can be left to third parties.
But, you still of course are one of the victims who will be screwed if those third parties fail to secure whichever blockchain you end up deciding to accept/use, or left holding the bag if/when they decide their blockchain is not worth the insane expense of securing it (especially in view of the lucrative profits to be made by suckering people into yet another insecure blockchain... why bother to secure yesterday's blockchain when it is so easy to make a sockpuppet and launch yet another blockchain?)
So unless your goal actually is to scam people, you'd serve your users/community best by picking a blockchain that might hopefully be among the very few (assuming there any at all) that can actually be secured and, also important, will actually be secured. (just because they can do something doesn't mean they will do it...)
I expect, statistically, that your goal actually is to try to sucker people into wasting resources / time / hashes / money / coins on yet another ultimately-un-secure-able blockchain, so expect you will now make all kinds of excuses for why the number of victims and the amount they will lose justifies your going ahead with your get rich quick scheme anyway, of course. But nice try with the getting rather old now verbiage about how your case is different you aren't out to harm anyone etc.
("But, your honour! I'm only planning manslaughter, not murder! I'm not out to harm anyone I'm just going to go ahead and harm them without intending to!")
-MarkM-
Actually, I want to move away from FIAT and the oppressive controls that keep humanity at war and divided. I want to add features to the site that encourage new users, including those not familiar with Bitcoin. Statistically I guess that is a fear assumption as most alt-coin seem to be ponzi schemes, which I have openly criticized myself. I guess you are right about keeping the system in the database though, perhaps it is unnecessary.
It is a Friday night so there might be typos.