Starting tret micro 0.025% after barrier issues on cream, gel, and adapalene

I’m using retinoids for anti-aging and have had a rough start of it. I used RoC Retinol Correxion Night Cream nightly for several months after weaning my youngest with no issues, but trouble started once I moved on to tret.

About 9 months ago, I was prescribed 0.025% tret cream and quit after a couple of months because I kept wrecking my barrier. I then tried 0.01% tret gel, not realizing that gel can be harsher, and that went even worse. After a break, I stepped down to 0.1% adapalene. I know it’s more acne-focused than anti-aging, but I wanted something less intense than tret.

Around that time, I started reading this sub and tweaking my morning routine, which helped a lot. I sandwiched adapalene for the first 2 months, then removed the top moisturizer layer, then eventually tried applying it without moisturizer. That’s when my barrier became unstable again: I seemed to disrupt it every 2-3 weeks despite only using adapalene only 3-4x weekly.

About two weeks ago, my 0.025% tret micro arrived from ADC. I’m now using it every 3 days, and so far, it's mostly fine. The morning after my second application, I had red splotches that looked like early barrier damage, but they resolved by the following morning. I plan to increase to 3x weekly in a week or two if everything continues smoothly.

I should add that I’ve also been using AzA for about 4 months and seem to have acclimated to it (it no longer stings on application unless my barrier is already compromised, in which case everything stings).

So here is my routine:

AM/Daytime:

• Water rinse only (even after slugging -- is that okay?)
• Finacea 15% azelaic acid (on damp skin)
• CeraVe Hyaluronic Acid Serum (right after AzA)
• Aestura 365 Atobarrier Cream (or Lotion if skin feels calm)
• SPF 50, Biore UV Aqua Rich or BOJ Relief Sun Aqua-Fresh (reapplied every 2 hours if outside)
• If I’m home, I reapply one of my moisturizers every 3-4 hours (I wear no face makeup and have had no breakouts so far)

PM (Tret Nights):

• CeraVe Makeup Removing Balm (eyes only)
• Vanicream Gentle Cleanser + konjac sponge every 2-3 days
• Mixsoon Bifida Essence (on damp skin, let dry 30+ mins)
• Revize Micro Tretinoin Gel 0.025% (right before bed -- should I wait longer before going to bed?)

PM (Rest Nights):

• CeraVe Balm (eyes only)
• Vanicream Cleanser + konjac every 2-3 days
• Mixsoon Bifida Essence
• CeraVe HA Serum or Neutrogena Hydroboost (about 1 min later)
• Aestura Cream or Lotion
• Vaseline 1-2x weekly if needed

My questions:

1. Do I need to stop side-sleeping if I’m using tret micro? I keep reading scary things about back sleeping, but then worry that those tiny little pillows for side sleepers might mess with my already fragile sleep. 
2. Am I ok to apply tret micro right before bed or do I need to give it more time to absorb?
3. After slugging with Vaseline, do I need a proper cleanser in the morning or is water enough?
4. If my barrier starts acting up, should I skip AzA and/or HA?
5. When my barrier struggles, I drop retinoids to every 3 days instead of stopping completely. Is that okay? If not, how long should a full break be and do I need to restart from zero afterwards?
6. I also own: Aestura Hydrogel, Neutrogena Hydroboost, Purito Oat Gel, and Bioderma Atoderm Intensive Baume. Would either of these be useful for my routine?
7. I’m reluctant to buy more products if I can avoid it. I was never “into” skincare, and the amount I’ve accumulated since starting retinoids already feels overwhelming. Please only suggest new products if something seems really off.