To answer your questions in order:
1) Daemonic summoning and, more generally, Daemonic rules are identical to the Black Legion/Chaos marine lists. Changing core rules like that are beyond the scope of this list.
2) The entry for Daemonic pact in the army list (pg 9) literally says "Allows the formation to summon daemons from the Daemon Pool"
3) Listing small arms as a weapon with a 15cm range is a basic Epic: Armageddon conceit, all lists do it and changing it here would be needless and counter-productive.
4) Arch-Heretic is indeed missing! good catch, will amend the list.
5) Icon Bearer is the only entry listed as a character.....because it is the only entry that is a character. Things like the Demagogue ir Space Marine Aspiring Champion are infantry, not characters. these are two very different things.
6) Listing all the specific transportable units is another Epic Armageddon list conceit (check any other list to confirm) and is in place to answer your second part; if a unit isn't listed as being transportable....then it's not transportable. This is complicated by the fact that the PDF does not seem to have rendered the notes text for the land transporter properly which I will fix for v0.2
7) the technical is literally a land transporter with a heavy stubber mounted on the back; I think it fits the list perfectly and was put in to replace the loss of Hydras.

I actually like the Alter and take it in all the lists. It could maybe use a points drop but even that I'm not convinced of.
9) 15cm move for the Hellfire cannon is unaltered from the original LatD list and is appropriate considering it's just a massive brass cannon on a wooden trolley. Also, consider that, because of the 15cm move, it can be set up as a garrison; that's 4 x MW4+ out to 75cm on overwatch at the beginning of the game.
10) Similarly, the Lord of battle crit is lifted directly from the original LatD list and represents the Lord of battle rampaging around in a bloodlust.
11) Daemonic Engine in the notes field is a holdover from how the original LatD list was structured and will be removed.
12) Daemonic Beasts are left out in error (I noted this in my first post)
13) Daemons, both lesser and greater, should be identical across this list and the Black Legion list.
14) the use of both Lost and the Damned and Stigmatus Coven is another holdover from the original Lost and the Damned list which did the same thing. We can revert all of one type to the other if needed.
15) Max 4 upgrades per coven is, once again, directly lifted from the original LatD list. The aim of this redux list wasn't a wholesale re-write but, with the removal of traitor guard maybe this can be relaxed.
16) you're right that there should be no cost next to "Up to two Daemon Scout Titans". Will be removed from v0.2
17) Silver towers should indeed list the formation as costing 325 pts, not each Tower costing 325 pts. Will be changed for v0.2
18) Chimeras and land transports are both 30cm move so speed is the same, and Leman Russ are too much of an iconic Guard unit.
maaaaaaaaaybee some kind of possessed ragnarok might be applicable, but I'd much rather see the existing Daemonic engines fleshed out and added in as support first.
19) I agree that the Alter is generally fine, but could potentially use a points drop (or maybe the addition of something like Leader).
With all that said, I'll get v0.2 of the list written up and published to this thread by this weekend.
Thanks for the feedback.