Speaking of Crawlers, pure psi is very powerful and some situations that are difficult for other characters are a breeze, but its weaknesses are the most profound of any build I've ever played. For example, not even a high-quality sturdy tactical vest, low-low (or medium-low, or low-medium) shield generator, vigorous belt, and some extra CON will prevent the stronger crossbow and knife users from annihilating me in a single turn unless I lock them down first, which is quite difficult if they're stealthy, because I don't have a massive Detection score and my Battleship Pyrokinesis spray-and-pray won't always hit them. Crawlers are similar, and although rarely actually deadly, they're costly in resources.
Furthermore, Plasma Sentries are incredibly difficult to kill (at least at my current level, 13) because they are robotic and immune to most/all shield-bypassing damaging psi abilities, meaning they can't be alpha struck in one round... after which the shield comes on and it takes an eternity and tons of psi points to finally wear them down.
Pure psi to me feels like a significantly more powerful and versatile stealth character, except with no stealth, evasion, dodge, lower Detection and fewer HP. Time will tell if this is a worthwhile tradeoff.
Electrokinetic Imprint helps somewhat with these situations now that I have it, and it may be that I need a few more levels under my belt as a buffer/boost. I've been ranging far and wide exploring the caves and procrastinating on doing most of the post-Depot quests.