I would really recommend forgetting clothing right now and focusing on the overall anatomy, there are some issues with the arms and hands for example. Keep it up!
Depends on the game. If you have a regular grid, attached can be better. Infinite runner for example. But if more organic results are needed, then modular is better.
So you'd say it's common practice to finish a dynamesh blockout of a creature for example, and then manually retopo a base mesh from it to subdivide + sculpt in zbrush?