Yes. Some will bleed off. But, one of its main jobs is to prevent disease created by destructive insects.
According to their website, yes.
It says small shrubs so I would use it. I would make sure you only spray the end and not the rest of the stem/branch.
Scotes outdoor cleaner plus oxiclean is my pick. There are others but seem to harsh. As always try a small spot to make sure it doesn't have a negative effect.
No. The SDS (MSDS) for Spectracide Pruning Seal is available on the homedepot.com product page for this spray sealant (basically, it appears to be an asphalt compound with a mineral spirits carrier and some Xylene quick-drying agent). Flex Seal, on the other hand, is a liquid rubber of some kind, with toluene and some aliphatic petroleum distillates, etc. (SDS is at https://sdsinventory.com/substances/accessSDS/SDS-101102-581b5448a15476.26351891 ). I wouldn't say that Flex Seal is necessarily a suitable material for sealing cuts or wounds on trees. Being 'rubber' it would also tend to trap moisture underneath for a Long time and that might not be good for the tree.
Homedepot.com sells an accessory that attaches to an extension pole (search for 314616562 ) This device snaps onto the round collar at the top of the spray can... but it will only fit certain size cans; some reviewers say it won't work with all brands of wasp & hornet spray, for instance. There are other similar devices on the market which utilize an adjustable band clamp to hold the can; search for "Aerosol Spray Can Extension Pole Adapter"
Yes. That’s what I bought it for.
There are several other good products that will better serve you for the pressure treated lumber use. I would do more research before using this product.
If the tree is a type that tends to grow new 'sprouts' around the cut-off limb ... this pruning seal will not typically prevent that. So, it will be necessary to cut those regrowth twigs off each Fall or winter to stop them from turning into new branches. However, it is VERY important -- when removing a limb -- to avoid cutting off or into the 'Branch Collar' so the wound will heal faster and properly. https://www.thedailygarden.us/garden-word-of-the-day/branch-collar
Home Depot use to as I have brought some there but any hardware store will carry it.