I get that you want people to be able to customise their load-out right from the start, but I think starting with a gem (or two) of every type is actually too much too soon. I'd say give us three random gems, maybe, weighted in such a way as to ensure we're capable of defending ourselves.
Hell, maybe you could even do something like: you automatically get one gem of type equivalent to settlement region plus one or two random gems, tiered at an appropriate level; for each settlement you find. Sure, everyone would start out therefore with one ice type gem but I think it adds a more reasonable curve to when you can make each sort of spell.
And I also think that (for good or ill) the profession books actually did add a non-trivial level of gating before. I didn't think they were terribly intuitive, as I've said - not least of all because their gating system was completely random - but I actually had to look for them. And what's more, I might find one and then bring it home and not get the option I wanted, so I'd have to go back out again.
Now, it's pretty simple to check where the ingredients you need are, go out into the world, collect some, come back, bam, spell's made. You can do that with all the spells at tier 1 right from the start at the moment. Obviously as you add more, the gem restriction comes into play - which is a proper restriction because you have to fight bosses to get gems.
In short, I support the removal of profession books but also agree with the sentiment that there needs to be more to the gating system and the way it presents unlocks to you, rather than the current "here's everything at level 1" approach it currently uses.