Just from watching that first vid as well as some more advice
-Against anyone with a fireball, pick ultra one. It goes through fireballs (make sure that you hold the control stick forward against far away opponents, neutral for mid screen opponents and back for up close opponents.
-If you are full screen from an enemy who just fired a projectile, use jaguar tooth. I prefer to be a LITTLE bit psychic about it (buffering motion at the same time the opponent is doing their attack basically) and this will come easily from playing a few rounds against someone and learning their habits.
Also, remember that if your opponent is in the corner and you hit them with an EX jaguar tooth, you can follow up with ultra 2, ultra 1 (not the full animation) RJ, EX RJ, or st.HK. When I play there are even times when a normal Jaguar tooth will allow me to follow up with a st.HK even when my opponent is not cornered, I believe it depends on where you are on the screen when you hit your opponent with the JT.
When mid screen against an opponent that you think will fireball, use a jaguar kick. You can also space jaguar kicks well enough to add to your pressure game from multiple distances, and apparently some uber pros can cross-up with it.
Adon is great for rushdown, but make sure you utilize some of his normals, they are very good. I am unsure of frame data, but st.HK is an awesome long reaching punish that can utterly shut some people down, as well as his st.MK being a great quick poke and apparently timed correctly, can be a good anti-air (but RJ is always the preferred AA move)
Obviously spamming the shit out of RJ like in that first video will get you wrecked by anyone with a fully functional brain stem and nervous system, but some of those randoms online will still let you give it to em.
Adon also has a fast dash ( apparently some people have used it to avoid akuma air gohadoukens) and pretty good cross up (j.MK)
Can you FADC? Adon builds meter really quick and has worthwhile normals too, so building meter with him is easy even though hes not a projectile character. FADC from a RJ (most people use MK RJ) into ultra 2.
If the opponent jumps and you hit them while they are in the air with an EX jaguar kick, you can follow up with u1 (im not sure if this is in the corner or anywhere, but they must be in the air)
There are some stickies that have all his BnB’s, specific matchup info and frame data as well i believe. GL with adon, when i am able to get my own xbox i will be going back to maining him and sagat
EDIT 1 BTW i have never tried it or seen anyone confirm it but i dont think jumping roundhouse combos into ultra, I might be wrong, but i havent heard of it)