Alternator best has been replaced 4-5 times in last 15k miles. Works for a while then starts to squeal. Tightening helps for a while then starts to squeal again. Any help is appreciated!

That's the inline six cylinder engine and I usually checked the plugs every 15K miles when I did my oil changes. I only used the OEM Volvo plugs as it ran best on that (low grade or premium, and I even tried Ethanol free gas). They lasted about 75K before I thought they looked a little worn.

The short answer is to replace them when they're worn.

Before replacing alternator testing should be done , is there B+ voltage at the heavier gage wire on the back of the alternator . Could have a blown fuse or fusible link . Your vehicle from what you have posted , isn't charging . Plus there is a regular fuse located in the under hood fuse box F1.13 - 10 amp this supply's B+ voltage to the orange with lit blue stripe wire at the three wire connector plugged into the alternator . The other two wires come from the PCM - engine computer . This charging system is computer controlled . Ford PCM controlled alternator testing

60k

Yes check the alternator, with volt meter and car running check voltage at battery, that will be alternator voltage out put, should have no less then 13.0 volts.But it sounds like your alternator has gone bad.Good luck

Sounds like you have a bad spot on the starter armateur...and will need to replace the starter.

If its the original, and you have over 50K miles then its probably a safe bet that your starter is bad, and will fail totally soon...if thats not the case now.

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/sean_54c3a3dc48a7773c

WELL THE CODES WOULD HELP A LOT BUT IT SOUND LIKE IT MAY BE LOCK UP IN TRANS MAY BE BUT CODES WOULD HELP

must be voltage regulater

does the check engine flash while driving, a quick test, cause I suspect the coil pack, when dark open the hood start the truck and with a water bottle spray the coil pack if you see sparks replace it, change many of those here ....

The negative number means the car should have had it's oil changed that many miles ago. Oil life starts at 100% for new oil & counts down every 10%. At 15% the display will always show, which means it's near time to change the oil.

usersteve83, your oil may have been changed but the timer not reset. Reset the timer as shown...
1. Turn ignition to the "ON" position. (do not start engine)
2. Press SEL/RESET repeatedly until the oil life indicator is displayed.
3. Press & hold the SEL/RESET for about 10 seconds until it blinks then let go of the button.
4. Press the SEL/RESET again for about 5 seconds or until the oil life indicator resets to 100%.

Wrench = Maintenance Minder: Symbol letter & number...
Symbol A - Relace engine oil.
Symbol B - Replace engine oil & filter, Inspect front & rear brakes, Check parking brake adjustment, Visually inpest the tie rods, suspension components,driveshaft boots, brake hoses & line (including ABS), all fluid levels & their conditions, exhaust system, fuel lines & connections.
Symbol 1 - Rotate tires.
Symbol 2 - Replace air cleaner element (dusty conditions every 15K miles) & replace dust & pollen filter (behind glovebox) every 15K miles if mainly dusty or city driving.
Symbol 3 - Replace transmission fluid.
Symbol 4 - Replace spark plugs.
Symbol 5 - Replace engine coolant.

All above are taken from the 2006 Civic EX owner's manual.

It's not your alternator, why would that cause your lights to flicker as it goes through the battery FIRST (read: it's a giant power filter/surge suppressor)?
A Nippondenso alternator should last for about 10 years or 150K miles or so, unless you are driving 100K miles a months, stop replacing the alternator.  
What does the noise sound like?  I think you have a serpentine belt,  is that correct?