Assuming VSC charges fees to the users of the tools it plans to make, is the plan to use those earnings to repay the investment from the DHF, or if not, what happens to the earnings from those fees ?

VSC will lock up Hive as part of it's consensus and burn a small amount of HBD as part of the fees taken for processing swaps. Already VSC has locked up over 50K Hive with more on the way as more nodes come online and stake.

Also, is it realistic to expect it to bring in an equivalent inward investment to Hive ? If so, over what period of time and how can it be objectively measured

Yes, once VSC launches it's liquidity pool where investors can earn 15% APR + LP APR we will aggressively target investors and get them bringing value into the ecosystem. Marketing is part of this budget, so no additional funds will be required.

We've already launched the VSC mainnet, now it is time for the stage stage of development.