SSD4, MIDI x's, 32-bit, overload & crash

Last night I recorded 2 longish jam tracks using EZKeys & Slate Drums 4.0 as plugins. Weird stuff happened:

The MIDI drum tracks all display "X's" in the regions. Never seen that before on drum tracks. Did I do something to cause that?

I recorded the kick & snare together on one track, then added ride & hihat parts in another pass. Although I had "create take folders" checked in Project Settings, all the drum parts ended up on the same track. So I separated the kick & snare parts using the option for overlapping tracks. Then I copy/pasted the ride & hat hits into a separate track ("new with duplicate settings"). In the process of editing, I solo'ed the different tracks to be sure I had separated everything correctly. Alas, Logic & the system started glitching, complaining, warning about too many plugins & lack of memory, & finally, saving the file & closing Logic. I tried re-opening the file but it crashed before I could do anything, even just play it. I tried to adjust the detail, sampling & Memory Guard functions in Slate Drums but Logic again says "there is not enough free memory to continue working with this project" & it saved the file & closed Logic again.

Before any of the drum editing above, everything played fine all the way through. Do I need to go into History & just delete all my edits? Copy the tracks into a new project?

I did use a template for the project, & found a thread here about a similar problem where I think Triplets suggested the template could be corrupted. If so, how can I tell, & how can I get my data into a new, non-template, blank project?

Admittedly, I have been running Logic in 32-bit. Clearly, 64-bit might handle Slate Drums better. Is it possible to change Logic to 64-bit without having to do a complete re-install? I only have a few plugins (EZKeys, BFD Eco, SSD Platinum 4.0, Addictive Drums Demo, Addictive Keys Demo, Nectar Elements, & maybe 1 or 2 more), so the AU re-validation process shouldn't be too horrible.

Additionally, I only have 4G RAM (planning to upgrade soon) & the original 5400 rpm system drive. All my SSD samples are on an external 7200 rpm drive, which is also my recording drive.

Would greatly appreciate some help troubleshooting here. Thank you.