If it was me, I would make the middle catching ability free. It is already limited in many ways. I would consider a cost to make it last until the monk's next turn. You activate it with a reaction, spend a point and you and deflect and return as many missiles shot at you that turn.
You would be...
It is theoretically possible for a Tiefling to have a parent from the lower planes and not be a Cambion especially if shape change was involved.
A shape changed dragon could have a half dragon child, but most likely it will be a child who could become a draconic ancestry sorcerer. My first 5e...
The way to do wild shape is like this:
Keep the templates.
Create themed packages that you can apply one to a template.
If you want to become a tanky bear, add the package to the land template that gives extra AC and HP.
If you want to be a giant spider, add the package that gives a poison...
The are the sellers of fine equines. Just remember not to look in it's mouth to see their health. The Giff take offense at that. Thus the saying
Never look a Giff horse in the mouth.
They are going to bog down combat especially the one where the DM has to roll to resist knockdown every hit and giving yourself nearly permanent advantage is a must have so there goes your level 4 pick.
Instead of a tier list, the best way would be by point value. It takes less room and shows how each race was balanced against each other though I would bet that they would find that they are not balanced with each other.
If they want players to have the option to have any mixed heritage we want, then they need to gives us mechanical rules to mix two races together instead of copping out and just saying pretend you are mixed.
We do not need WotC to tell us that we can use our imagination.
If they allow whoever it was that did the abomination that is the Halfling art anywhere near the phb, I will got to WotC HQ with tar and feathers because I am old school.