One thing that happens with my disc is a few times it'll switch from english dub to Japanese and then sometimes from english dub to subtitles. But only for a few seconds. Anyone else have this problem?.
That's due to the difference in length between the original US and Japanese episodes, the US versions made minor cuts for length; it's not a disc problem.
Is Hayata the same actor who went on to play Kikaida? I swear they look alike.
No, they are two different actors. Hayata was played by Susumu Kurobe and Jiro in KIKAIDA was played by Daisuke Ban. Kurobe played villains in some Toku shows that followed, while Ban appeared in many other Toku shows, including playing other superheroes (Inazuman, Ninja Captor 7, Battle Cossack).
Also, I noticed Classic Rider Ally, Tachibana is in it!!!.
Akiji Kobayashi was chosen for KAMEN RIDER because of his role in ULTRAMAN.
1. How come the mummy get killed by the laser so easily? Just like four-legged-dragon. That confused me a bit.
I don't know exactly why you're confused. The Mummy wasn't invincible, so Arashi's Spidershot -- a very powerful weapon -- took him out. As for Dodongo, the monster was vunerable once his major defense (his eyes and eye rays) were destroyed.
2. I was wondering if they asked the Toho company to use Godzilla to be in Ultraman.
No. ULTRAMAN was produced by Tsuburaya Productions. Tsuburaya Productions was founded by Eiji Tsuburaya. Eiji Tsuburaya was the the master of the Visual Effects Department at Toho and wielded a lot of power at that studio (he put them on the international map with his effects films like GODZILLA). Tsuburaya just took what he wanted from his effects department at Toho to use on ULTRAMAN -- even if Toho objected, they wouldn't and couldn't have stopped him.
I seriously hope they will release Ultraseven. I heard so many fans that loved Ultraseven.
Don't hold your breath; I don't think that Tsuburaya Productions will let Chaiyo get that far...