Where do you live?

Blow it - the hose is plenty long.

You should buy those plastic things but you could just skip the last 12 inches or so - not ideal.

I live in Atlanta.

better do your air sealing at attic floor to inside house first. recessed lights, bath fans stove vents etc.

any duct sealing should also be done prior to insulation
install.
plenum to equipment connection, duct takeoff at plenum
and supply boxes to attic floor.
return caulked.

best of luck

I have not read where fiberglass batts cannot be installed over blown in insulation. However the general consensus is it is better to add more blown insulation than layering a batt. I would be concerned about the batt sagging if you laid it perpendicualar to the joists. If you laid the batt parrallel, then the layer may be uneven.

There are several Youtube videos showing blown in insulation installation. It is a messy job, but doable for the DIYer.

there is no problem with unfaced batts over blown.
to install batts over existing blown it would
need to be unfaced batts.
you may need to special order it from hd or lowes.

I'd go batts over cellulose anyday. not everyone
agrees, but the fine particles from cellulose
finds its way into your living space via
cracks between attic and living space.

you should invest in the air sealing first.
and duct sealing if your ducts are in the attic.
lots of humdity issues in our area.
you don't want to filter hot humid attic
air thru the insulation and into your home.
caulk and mastics are easy to work with.

best of luck