Are we going by the AT fluff - or the newer stuff in the horus heresy books? I'm 5 books into the HH series, so I can lend a hand there.
Marines:
Assault squads - I'd say yes - the world eaters were all about the assault even before they turned.
Scouts - No sign of scouts, so I'd agree.
Dreds - there are dreds, though they look like the old epic dreds, not the current ones.
Bikes - I havent read anything about bikes yet, of any type.
Speeders - same with speeders, though I know they had basic ones.
Other Vehicles - All basic, no fancy upgrades
Thunderhawks - They have them, but they are brand new. Marines use "Storm Birds" - big arse transports. Thunderhawks are considered "small" by comparison.
Guard - cant say much - they're basically bullet shields in the books so far.
Imperial Navy - According to old epic fluff, the gift of flight was lost during the age of strife - I'd say no to all "inner-atmosphere" aircraft.
Titans - All of those are present. An imperator was present on Istvaan III - The first battle of the Heresy. And it survived a massive planet-wide virus bombing, followed by a planet consuming firebombing.
Something to add to the AdMech - Ordinatus Mars was built for the sole purpose of defeating the traitors in the AdMech that were holed up in the Jerico Tower on Mars.