Consensus opinion for small business, else; PoS?

In the even a small business doesn't want to raise a full fletch ICO, and use engineers to build a blockchain specific for their company I would assume choosing an existing maintain to build a DApp off (eg. Tron, Eth). But can we create a simple inexpensive consensus alone, or on top of another platform?

How difficult is it to program own consensus eg. Customer sends request to the business, business mining centre verifies first block on their end. Block is then sent to original user to confirm who the essentially get rebated some of the fee for partaking in the the witness verification. the final block selects another user at random and rewards them. No physical mining system is wanted (like POW)
This is the idea I had, since we are talking small business, so somewhat a localised consensus would be ok, ultimately still ruling out interference from business. Or is there a lot I this theory I am missing. - I did only spend a couple hours getting it for head to paper, and thought I post to experts while I troubleshoot it - for alternate answers/solutions and knowledge.

Alternatively if that's a sloppy chain or far too difficult for a non-ICO self funded business to achieve:
If existing chain is used and a utility token is needed, then;
Assuming a customer that interacts with the business, sends a request to do with a product of our business and charged a fee for the company and network as usual, the blocks need to be verified without POW. PoS comes to mind, in which the company could stake most coins as the equity and collateral wallets.
If another mainchain is used, does a token HAVE to be used? Using a utility token to power the chain will result in additional costs as the token due to certain conversions needed.

I am just and individual with ideas and much to learn. Any comments short or long for me to look into?

BONUS QUESTION. Can a bitcoin be send from wallet to wallet, or wallet to exchange etc (using APIs etc) via a different mainchain EG Tron. (chose Tron because PoS)

Other recommendations?

If I'm way off... how are future small businesses who need decentralisation able to achieve this, as programming specific to company functions would be needed? Ive only noticed current ICOs raise a lot because they need a lot. I want to know how to go decentralised without the fund raise, and as simple and efficient as possible.