22A Someone who is 'dynamic'...ie a dynamist...is someone who wants things to get moving...hence the 'proposing motion' element and 'dynamism' is the theory that explains the phenomena of the universe, according to Chambers.
14D Crosswords frequently use the idea of 'time' being the old 'enemy', so 'enemy' is one time, 'age' is another time and the abbreviation 't' is a third. All three are around 'n' for 'name'. An agent/spy has been referred to as 'our man' as in the novel Our Man in Havana, so "not our man" must be an enemy agent.
Personally, I lose interest in a crossword grid once I've completed it and don't bother with the additional 'cryptography' sometimes asked for. However, this one seems to have drawn so much interest that I did have a look for the coded information. I didn't see it either, I confess.