Ahrimon
Bourbon and Dice
I am pretty sure you will be able to see my point that characters with 21+ AC EVERY combat round are "too indistructible" (add in Haste and we are at AC 23). And thanks to mage armor the fighter NEVER will have more AC, actually never even the same. The fighter will have AC 18 or 20 (1H or 2H, and as 1H+Shield is boring to play probably AC 18). With the Spell Slots it is still playable, but with the Spellpoints - unless they have some special rule to prevent problems here, even I - who likes to use the Shield spell myselves ^^ - sees problems here.
To me, this is a table issue and not a game issue. The modules are there as options. They're not going to fully playtest and balance every option or combination of options. That would exponentially increase the development time. They've provided a working solution with the caveat that there may be some side effects depending on any number of things. If wizards and warriors casting shield every round concerns you, don't use the point option.
Creating magic items is an optional rule. Buying magic items is an optional rule. What items the players even get or have access to is entirely up to the DM. So if the DM hands out +3 plate and +3 shields, it's the DM accepting that he or she is giving a player a massive power boost.
If, as a DM, I gave every player +3 armor and weapons, I would also lower the default XP because fights are no longer as challenging. Then, I could increase the challenge without them getting extra XP. XP is based on the challenge and the challenge is based on the assumption of no magic items.