I'm pretty far in the game, almost finished the main story and all of Luna's story, still have a bit to go with Gracie and Antonio's wife (forgot her name).
I've done all the event contracts that have been available. But for my game so far, I've only had 5 contracts come up and they're all in the D level. Do I have to 100% complete all of these contracts to go further in the game? Are there only D level contracts available at this time? Do the contracts have any relation to the main game or are they just for fun?
Just to add a little bit to what Cartageno replied to you above; it's really gonna depend on which mode you're playing this game (I always choose Full experience), but it's recommended to max out the contracts 100% because what you get basically changes not just with the special renders (and money) but also equipment.
For example, the best equipment reward for the contract "Nimble Fingers" is rare hardened gloves.
If you did just relatively well in that contracts first completion, it's most likely you'll be given uncommon hardened gloves.
So to get the rare hardened gloves, you'll need to go back to that contract and try it again, do better to get them (they of course are more valuable than the uncommon ones, and have higher stats boosts).
And that's part of the point of the contracts, more often than not, you'll not get a "perfect run" in your first crack at them and it is expected for you to go through again, that is if you want the better equipment.
Hopes (the dev) said that the game at this point is around 30% done.
