What's the difference between an RCA tv model RLDED5098-F-UHD and model RLDED5098-E-UHD?

Your LED backlights

This set has a block fuse that sits to the right of the power plug. Problem is replacing it won't fix a thing, it will blow the one you put in. this could be a shorted P/S diode, FET, zener diode ect on the hot side of the board or it could be a shorted component on the cold side, that will blow the fuse as well. Buy a new board, don't try to fix it.

The one they sent is an older model by 1.
Having said that it is a very minor change so the question is "does this tv have all the functions of the F model and is the picture ok??

Just to make a note, the RCA 4k UHD TV models such as RTU-**** are horrible for finding remote codes. These TV's are actually made by Curtis. The manua will give you the remote code.. sort of. So far it seems as though all of them are NEC format with a code of A05F .. along with a full key map.. useless for a universal remote, useful for a Windows ore linux serial based IR transmitter.. and maybe a lead to the 5 digit code. NEC codes did not work, seems to be NEC format, which covers 95% of all remotes, NOT NEC product.

Yes most like likely

Yes it will be.

you said ; unfortunatly uhd player ? maybe you mean Ultra HD player, so try to unistall your UHD and reboot , than install again with a newer version or an older one, and see if it's works or not.

As this is a top-of-the-line, newly released model UHD TV, it may very well have features that are not yet recognized by universal remotes and thus haven't been incorporated into them. Changes are within a few months to a year, remotes will catch up. This is price you pay to stay on the cutting edge.....

RCA cable from Samsungs front left and right jacks.