Hopefully someone with TW HD in Dayton can soon post updated info which will hopefully better help answer some of your questions than I can, however, you can also find info on HD from TWC Dayton from posters with TW HD in Dayton on previous pages of this thread.
From what I recall from previous posters here with Dayton TW HD, last I heard, I do believe they have HBO-HD and Showtime HD available. I can't say for sure, but I'm skeptical of the accuracy of the info you have gotten from the TW rep, especially so where some of the the "channel tuning" info that was provided to you is concerned, and also, One thing I do know is, you won't get HD or even "Fox Widescreen" from the Fox Dayton station, which I'm fairly sure is what TW Dayton has available.
Concerning the local digital Over-the-air broadcast stations/networks, the last I heard the following 3 stations are what TW Dayton offers, along with notes on the general "quality of service" we get from these stations :
WKEF-DT (NBC HD) - Although "in general" they've gotten better about it lately, They are sometimes quite sporadic about providing NBC HD - Last night when I checked Leno for example, it was 4x3 SD on WKEF-DT, whearas the HD for Leno was fine from the Cincinnati NBC HD station. This station is owned by Sinclair broadcasting, so it's a bit of a miracle we get HD from them at all, considering Sinclair stations HD "record". I do believe it is because of folks at the station that we are getting NBC HD from them. I believe their switching is manual, however, so sometimes they need to be called and reminded to "flip the HD switch".
WRGT-DT (Fox Digital) -- They Don't Do any Fox widescreen or HD however, it's 4x3 480i SD 0nly. I wouldn't hold my breath for widescreen or Fox HD.(when Fox starts doing HD within the next year or so that is). This station is also controlled by Sinclair, BTW.
WPTD-DT (PBS/Think TV). WPTD-DT has HD in the evenings, at which time they drop to a single SD subchannel(simulcast of 16 analog) along with the HD -- Which still isn't really "enough" bandwidth for HD to look it's best(free from compression artifacts). The rest of the time, they have 4 SD channels/programming services. From my understanding of previous posts from TW HD customers, they provide all these subchannels/programming services when available.
Concerning the other Dayton HD/Digital stations that are on the air(pretty much all of them are), the last I heard, WDTN-DT(ABC HD Dayton) and WHIO-DT (CBS HD Dayton) were still in "negotiations" with TW for HD carriage, but hopefully they've added them by now. Without info from someone who has TW HD in Dayton however, I wouldn't count on it though. Don't have any info on WBDT-DT Dayton(WB - Owned by ACME) and TW, but, WBDT-DT is like WRGT-DT, they only do 4x3 480i SD, so there is little benefit over getting their analog station.
Also, although Dayton area Cable does carry some Cincinnati analog stations(at least they used to), and, they are well within Cincy stations "grade B" signal contours, I don't believe Dayton cable carries any of the Cincinnati Digital stations. However, most locations(South of I-70) in Dayton should have good luck pulling in most of the Cincinnati area stations given a decent outdoor antenna setup, and locations around, or East of I-675 should have a good shot at Columbus. These are the Cincy digital stations which should be receivable from Dayton:
WCPO-DT (ABC HD + a Local HD demo loop/etc. occasionally)
WKRC-DT (CBS HD, "usually" Paramount's HD One Movies, occasioanal Local HD demo loops, and for the Last two years, an excellent Multicamera(8) HD production of the WEBN/Riverfest Fireworks in Cincinnati .
WXIX-DT (Fox Widescreen(480p) and hopefully Fox HD In the next year or so, when Fox makes it available/etc)
WCET-DT (PBS HD/Multicasting - not much PBS HD except tuesday nights, unfortunetly - They've also shown a couple of locally produced HD programs, one of which I recall was on Tall Stacks 99' in Cincinnati)
WLWT-DT (NBC HD)
WSTR-DT (WB - 480i SD only, no HD unfortunetly - Owned by Sinclair, BTW)
WPTO-DT (PBS/ThinkTV) Is not on the air yet, but last I talked with them, they have plans for PBS HD/Multicasting, I believe with a different schedule/programming services than what is the case on WPTD-DT Dayton -- They will be broadcasting from WXIX Cincy's tower, and should be fairly easily receivable from Dayton. Last I heard, they planned on being on the air by late summer 2003.
WCVN-DT (KET/PBS) in Covington, KY is probably out of range for most in Dayton, except perhaps for those in high spots and/or with hi-gain antenna setups ...
WKOI-DT (TBN - religious - No HD) Richmond, IN(tower near Oxford, Ohio) is probably not very receivable from Dayton currently as they are using a very directional transmittingantenna which favors only their community of License, Richmond, In, which is some 30 Miles Northwest of their tower.
The UPN Cincinnati station does not have a seperate DTV channel allocation from the FCC, they will probably switch to digital/HD only at some point when they feel there are enough digital viewers(probably be quite a few years though), and drop their analog service at that time.
Columbus wise, the following stations are probably currently reachable from I-675 or farther east:
WWHO-DT Chillocothe( UPN/WB, and Paramount's HD-One Movie package -- WITH WB HD, and I assume will Have UPN HD when it becomes available)
WBNS-DT Columbus (CBS HD)
WSYX-DT Columbus (ABC HD)
WCMH-DT Columbus (NBC HD)
The PBS station in Columbus is not yet on the air, The Fox Station is currently at low power and thus would probably be difficult to receive from Dayton/Springfield area on a regular basis, with plans to go to high power in 6~12 Months. The Fox station does do Fox Widescreen currently however, although I believe it is at 480i 16x9.
Concerning HD from dish or directTV, keep in mind, You can't presently(or for the forseeable future) get HD/DTV locals, or HD from the broadcast networks via the sat dish, you'll need OTA/antenna for HD from CBS, NBC, PBS/etc.
While I believe Dish network does(or used to) carry at least the CBS HD feed, You need a waiver from the local CBS station in order to receive it, and I doubt if WHIO-DT would be willing to comply. Although, I don't know why one would not want to receive their HD locals OTA, as there are no monthly bills, and the hardware requirements(antenna, STB -- Which you'll have anyway for OTA if you go the DBS route) are about the same as a year or less of cable subscription, and yet the setup(outdoor directional antenna recommended, with rotor if necesssary) will last for decades(barring disaster).
Hope some of this helps, Let us know how it turns out, once you can relax and enjoy some HD, I think you'll find all these headaches to be "worth it" ...