I didn't want to make a big deal of the rock crawling, but thought it worth mentioning that the skills involved in doing it are nonetheless good to acquire and practice even if you plan to stay off the rocks. It's because I learned this in the wilds of southern Indiana in my FJ55 soon after I bought it. Was poking around with some friends looking for interesting trails. This was somewhere in Brown County or perhaps eastern Monroe County. Went down a trail that turned out to be badly washed and off kilter. Managed to stuff the right rear quarter panel into the bank when I lost situational awareness of where my right rear tire was. Here's a pic when we returned a few months later and someone had helpfully dozered things to make it easy to get back in there, IIRC the start of someone's housing subdivision in the woods.
That's my buddy David, laughing at the situation, because we almost didn't get out of there that day and now it was so smooth, easy, and even by golly, graveled. The brown patch on the rear of the Pig is my mark of shame for not paying attention to the fact I wasn't driving a Subaru anymore.
On-board air is worth the trouble if you do a lot of airing up. There are some decent portable units that will do that job and provide some additional flexibility that a bolted-on system won't. Especially for overlanding, it's handy to have a system that can be moved or lent out. So that's where we're at. I have an older top of the line Harbor Freight knockoff of a Puma(?), which isn't that much more expensive than HF via online sources.
On ABS delete, it's turned off in 4 Low, which is the only place where it might IMO tend to cause trouble except in the most exotic of circumstances, so a non-issue as far as need for a delete goes. I've had it work a couple of times on road and been happy that it did. Eveb if I thought I was quicker and smarter than it when I was young (I wasn't) I'm definitely not now. Then there is the whole issue of deleting a major safety feature that was applied by the manufacturer and how insurance companies might see that.
LSPV delete, hmm, jury's still out. The basic argument is that things like airbags tend to throw off how the LSPV works, particularly when used to compensate for trailer weight's effect on rear suspension height. Maybe, I haven't found it to be an issue yet, but haven't been to Colorado with the trailer yet either. In any case, Toyota says to have brakes on your trailer if it's over 1,000 lbs. IMO, having the trailer braked deals with any issues that would otherwise arise from any effects on the LSPV. One is in the plans here. So more testing needs to be done here, so YMMV, but those are my current thoughts on the topic.