Whew! Let's take one thing at a time.
The extractor needs frequent retensioning.
Sheepdip. If the day comes that I can't take a good quality extractor and get 50,000 rounds from it without having to do anything beyond periodic cleaning, I'll quit. I've got one that I took out of a 1918 Black Army Colt...adjusted the tension...installed it in a range beater, and it lasted for years. Of course, I use proper magazines in my pistols, and that has a lot to do with it.
1911s are finicky feeders/The need modification by a pro before they'll feed anything but hardball.
More of the same. I own several original/correct USGI pistols ranging from 1913 to 1945 production that function perfectly with hardball...hollowpoints...and even 200-grain lead SWCs of the Hensley & Gibbs #68 design...and they do it from the old "Hardball Only" magazines.
If they rattle like a box of bolts, they're reliable.
Sometimes...but new USGI and old commercial Government Models didn't rattle like that when they were new. A pistol that's too loose can be worse than one that's too tight. Loose doesn't guarantee reliability any more than tight guarantees accuracy, and a tight pistol can be just as reliable as a loose one and it doesn't offer the wide spaces for dirt and grit to enter.
The magazine is critical...and the same holds true for any self-loading arm. The problem with 1911 magazines is that so many are made to sell rather than made properly, and just because the gun is functioning is no guarantee that it's frunctioning correctly. See the extractor/magazine connection.
I have a pair of early 1991A1 Colts that I bought specifically for range use...and I've done my level best to break those pistols without any conspicious success. I tightened up the slide to frame fit at 75,000 rounds and installed new barrels. I replaced one MIM disconnect at that time...not because it malfunctioned, but because it was looking a little worn. They're now on their third barrels and passed 375,000 rounds collectively last year, when I stopped keeping track.
Both are still operating on their original MIM sears, and one with the original disconnect. Both have their original magazine catches...hammers...spring guides...spring plugs...thumb safeties...(I replaced the grip safeties with King's Drop-ins to stop blistering the web of my hand). One slidestop broke the lug at the 100,000 round mark. The other is OEM. I restaked both plunger tubes early on, just because they weren't properly staked...which is par for the course these days. Neither has given any further trouble. All pins are original, including the plunger assembly and spring.
I replaced the firing pin stops with fitted, small-radius stops as is my SOP.
I replaced both extractors with Wilson Heavy-Duty extractors when I refitted the frames...not because they were causing problems...but just because. They're still there. I had to retension them once because the rims on my much-reloaded cases had grown and they'd self-adjusted to the new diameter. When I switched to a new lot of brass...I got weak ejection, so I readjusted both. No further problems. Both used extractors went on to do duty in other pistols.
I replaced the triggers with solid aluminum triggers so I could trim them to length to suit my hand. Sights are original but modified for my eyes. Neither one has lost a front sight.
One never failed to feed, extract, or eject until about 2 years ago. I had a failure to go to battery that I attributed to a bad cartridge. One malfunction in 18 years. One.
The other gave a little feed trouble after I replaced the first barrel. 15 minute cure. I've had a total of about a dozen malfunctions with that one...always with my reloaded ammo, and always with lead SWCs. A dozen in 18 years. This is the one that broke the slidestop. It didn't shut the gun down, and all it wouldn't do was lock the slide on empty. Aside from that, neither gun has ever failed in that function. Not once.
Neither gun has ever been touched by a Dremel. Any polishing is the result of shooting them. Neither one has had any sort of "Special, Super-Secret Gunsmiffin' Tricks" performed on it.
Again...The pistol was designed to function. If it's correctly built to spec and fed decent ammunition from proper magazines...it will function. It's a machine. It doesn't have a choice.