I am in the same boat as you. But using 12.16 (and it allows me to change the default search engine).

From one that's not in the pre-set list? Because I tried 12.15-12.17 with clean installs, and while I can change the default search to Startpage (my preferred search engine), when I close and open the browser again it's set to Google.

Damn.. I guess you are right. I tried changing to some different engines and it wont stay after I close it...
I probably did not notice because I can't remember for how long I'm using DuckDuckGo, which I'll have to change too, after the last update... (geez, what's happening?)

I switch from Opera to Firefox long time ago, since stupid adobe plugins destroy Opera making it slower and crash too often, then I switch from Firefox to Chrome, not so long ago, when once again abobe plugins make it impossible to use it (once more slower, crashing frequently). Finally I comeback to Firefox when a new version become stable.
Does anyone else realize this lame and despicable practice that adobe and google are using to force you to use chrome? I'm the only conspiranoid here?

I know, which is one reason I switched to Pale Moon, as I said.
While Moonchild doesn't build Pale Moon for Linux himself, PM4Linux is an authorised port, which is why it can bear the Pale Moon name and logo.
http://www.palemoon.org/contributed-builds.shtml

You sound a lot like moderators at mozillaZine. Always shouting that Palemoon is simply reskinned Firefox with some code changes which is simply no true. Moonchild said that he will never implement Australis in Palemoon. We will see what happens when next Firefox ESR is released, but I am sure someone will find a way how to avoid it be it Moonchild or someone else. One thing is for sure I am not using Chromefox again.

It's interesting to see Chrome's impact on all of the competitor browsers, though. Basically since Chrome's inception, all of the competing browsers have basically turned into an re-skinned version of Chrome. Nice compliment to Google, I suppose. ._.

There is big difference between real fork and "customized version", you see.
For example, Maria DB is REAL fork of MySQL. they have enough power and exp to maintain code, LibreOffice os REAL fork of OpenOffficeOrg. Palemoon, just like Flock previously - is not so real fork. Yes, they do work and and do it well, but i literally dont see how they going to support WHOLE firefox codebase, especially since some very significant changes is coming, like e10s project - process isolation, sandboxed tabs and so on.

Like I said we will see when the next ESR is released. But even if Australis woud be implemented in a way that it cannot be simply "tweaked" I am sure Moonchild will try his best to minimize it and restore the old UI. Or maybe some new browser will jump on the scene or some people will join forces wit Moonchild and try to make Palemoon more sustainable and I woudnt be suprised if Palemoon popularity skyrocketed when Mozilla release their silent updates and force Australis even for people that use older version of Firefox. One thing is for certain tho, mozilla shoot themself in a foot first with mr.Eich debacle and than with this Chrome like UI and the feedback graph on their site shows it.

Ok, then let me ask you - that exactly is not OK to you in Australis?
When i first seen it - in Nigltly! MONTHS before most users so irritated now, i was super unhappy. It was SLOW, it was NOT customizeble at all, its broke tons of addons and useful functions. It was plain awful and i was writing posts about "mozilla gone crazy with ChromeFox".
ime is passes. Some functions, like easy access to classic menu - YES, it was REMOVED initially was returned, some options was changed and so on. Situation. generally. improved. Right now its mostly "as much Ok as it was before it" to me. OFC, some addodns is still broken, especially one who heavily tinker UI, but it was inevitable.
I still cannot say i understand FOR WHAT it was done, though, but i adapted to it. Some recent changes, which you probably will not see if yo not use Nightly, i even like - like copy of navigation buttons in right-click context-menu.
Try to bear with it?

Won't use opera even if you give me money, that browser is horrid... don't like it for some reason.

To begin with removal of some ui tweaks like tabs under the url bar, no add-on bar at the bottom, bookmark button now merged with bookmark menu... etc and to top it all of the icons in the customize menu look like they were made for a freakin tablet. I understand that some people like it and I am not pointing finger at them or trying to say they are wrong about Australis (most of these people probably dont even know that older versions of Firefox had add-on bar etc. so they wont probably notice any difference), but I always had a CHOICE to tweak Firefox how I wanted. I coud right now make PaleMoon look like Firefox 29 with Australis. But Mozilla said nope we are gona force it down on you. And last time something similiar happened was with Windows 8 and look how that turned up.

If the changes are good why not. I am sure that someone at Microsoft was working their butt off with the new taskbar and windows explorer, but someone from management said now slap Metro on it. Same with Firefox i suppose. I just jumped ship and now I am sailing on a browser that doesnt get in my way.

I don't think Ballmer or the other upper guys sit and design GUIs at Microsoft. What it happened, at least what I think it happened, is that the upper hierarchy guys wanted something identical on both mobile and desktop, and Metro was the best thing their design team came with.