I remember being intimidated about boosting initially as well. However, my experience was different.
get mineral harvesting working
get distracted by other pressing needs
panic about full terminals
quickly hack up some code to sell minerals on the market.
Use my new found credits to manually buy tier 3 heal boosts
Ruthlessly smash my neighbors with boosted healers.
I think the boosting via the market flow is good enough. A tier 0 boost flow could still enhance the game, but it is not strictly fixing a problem the current flow doesn't already cover.
Other thoughts on tier 0 boosts.
To be clear each boost will only apply to a single body part type. It won't be possible to have U boost both attack and harvest.
Either G, OH, ZK, and UL should either all be tier 0 boosts or none of them (None is probably the right choice since they all require reactions anyway).
I like the consistency of using O, H, and X as well as Z, U, L , and K as tier 0 boosts (make sure that minerals in your first few rooms always are able to boost something).
tier 0 boost should be LESS than half as good as tier 1. Again the point of tier 0 is get a player going while still providing a strong incentive to use the regular boosts.
The tier 0 boosts should target noob tasks.
Absolutely no TOUGH, HEAL, or dismantle boosts.
I don't think upgrade boosts should be available as tier 0 boosts either. Upgrade boosts are the most commonly used boost and keeping them as tier 1-3 provides a good incentive to write reaction or market code.
Probably no MOVE, ATTACK, or RANGED_ATTACK boosts, since new players don't really need to be attacking or defending with more than towers and unboosted defenders.
That leaves:
harvest
repair
build
carry