O Sensei's techniques (obviously not just his) and teachings, are these performed large and slow at first and statically for a beginner and then should these techniques become smaller and smaller trying to internalise these movements until they become part of our body movement, and the outward movements become less and less until they aren't obvious externally??
Yes and no, IMO. On one hand, learning big movements is important for developing the free movement and lightness that is essential to good aikido. Once you can do that, your technique can get smaller and smaller *without* being muscular. On the other hand, the big flowing technique doesn't actually work (without a cooperating uke) without a lot of skills that beginners just don't have.
Likewise, static practice is useful because it gives you the time to really feel what's going on, but it can easily reinforce bad habits.