It's about 2 inches from the bottom but the vessel has a wider diameter so the sediment volume will be greater than with a regular 5 gallon bucket. Get it with the metal spigot. The built in handles are really nice

You will be fine. The spigot is about 2 inches from bottom. If your still not sure you can slightly tilt the fermenter back with a wedge which will help keep the lees and solids on bottom and not in your cider.

about 3/4 of an inch maybe slightly more

I usually end up with about an inch of liquid/sludge after racking off my beer. I've never had an issue with solids getting pulled in when draining.

You get the cap and o-ring the rubber stopper the spigot and o-ring for it and a cap for either the top or spigot hole same threads. The smaller cap also has the same o-ring. I suggest getting a spare o-ring for the main lid for emergencies.

Everything u see in the pic air lock lid spigot and gaskets

Yes I did a test and let's say...keep your glass and stainless for vacuum degassing

I’ve not put mine under negative pressure. However I have put it under positive pressure up to 5psi. The fermenter is fairly thick plastic but it will start to distort around 5 psi. Hope this helps.

It's fairly solid but it's still just HDPE and not rated for pressure (including vacuum pressures)

Your units don’t make sense do you mean in-Hg or mm-Hg? Anyway these fermenters can handle a small overpressure but will readily collapse under any significant vacuum.

Make sure you remove the valve and fully clean it. I think it's much more likely that the valve is infected (or your autosiphon if you're using one) than scratches in the inside causing the infection. I use a stainless autosiphon and just discovered that I should fully disassemble the bottom part (so that I can see the check valve ball and o-ring that holds it in and whatnot). There was a tiny bit of gunk down there that needed cleaning despite starsan use immediately before and after siphoning. Another sneaky place that needs cleaning are the insides of the QD's for your kegs if you are kegging. Use a flathead screwdriver (or butter knife) and unscrew the top. Make sure you keep up with all the little springs and plastic bits. I usually toss them inside my fermenter if I'm wasting the water to fill it up with PBW. That's also a good opportunity to fill it with old bottles that you want to remove the labels from.

I use PBW soak after every batch. Then I normally use a sanitizing solution of potassium metabisuphite just prior to the next use. I give it about 15 minutes to sanitize and then about 5 - 10 minutes to drip/drain- do not rinse and does not need to be dry before use. This also works well with bottles kegs and other items that are difficult to dry before use. Keep in mind sanitizing with products like Iodophor and Star San requires items to air dry before use. The drying process is inherent to their mechanism of sanitization.

I only use the white (Mr. Clean) sponges or generics and fragrance free detergents on plastics. For your problem if you can feel the scratches I would sand with a very fine sand paper on the scratches only very lightly. I really like this fermenter.

A soak with PBW then hot water rinse then soak with Star San usually will solve this problem... I usually replace them if this does not work...

I have never had an issue with this fermenter.. Is it new and has scratches or did you clean with something that caused the scratches? I use StarSan to sanitize and PBW to clean..

The way to save this fermenter would be to add boiling water directly into the fermenter and let that soak. The plastic will withstand the hot temperature and warm up to pasteurize it. Using another fermenter and eliminating this variable is a great idea to double check in the meantime.