Delighted with new XPS13 DE -- question about optimizing for SSD

My XPS 13 DE (the i5 with 128G SSD) with 12.4.4 LTS just arrived and everything about it has been great. The fit and finish are beautiful. The software setup ran smoothly, and I liked the option to encrypt the home folder. Basically, everything worked right out of the box: wireless, backlit keyboard, connection to wireless printer, etc. I'm not a developer or a linux guru, but have installed Debian, Mint and Ubuntu on prior machines. There always seemed to be a problem or two that I never could figure out, no matter how many hours I spent in forums and with google. Not this time--I was up and running productively from the outset. This might be a game changer for Dell/Ubuntu. The team who put this hardware and software together should be very proud of the finished product.

I had a question about the SSD. Based on research I had done before, there were a number of settings that were recommended to avoid prematurely wearing it down. Some of these were implemented on the XPS 13 DE. But some weren't, and I didn't know whether that was intentional. Here is the list I had of suggested optimizations, versus what I found on my new machine:

1. 10% of drive left unformatted for overprovisioning. Yes.

2. Activate AHCI for SATA in BIOS/UEFI. Yes.

3. Add "noatime" in line for root partition in /etc/fstab. No

4. Automatic trim (in /etc/rc.local or /etc/chron.daily/trim). No

5. Add lines for vm.swappiness=1 and vm.vfs_cache_pressure=50 at the bottom of /etc/sysctl.conf. No, swappiness set at 60 and second line not added.

6. Change scheduler to "deadline." No, is CFQ.

7. Disable hibernation. No, set to hibernate when power is low (or maybe this is really a Yes, since it should happen only in rare circumstances where it would be beneficial).

8. In Firefox, set cache to 0. No.

There is conflicting advice online about these settings. Does Dell recommend that any of the changes described in items 3-8 above should be implemented?

Thanks!