Yes ofcourse that will be so good cuz you will feel that you are in your own place and relaxed and can take your self where ever you want by meditation
If meditation if for self reflection then there should be no problem with you doing yoga or other postures. Remember to listen to your body and clear your mind.
Practically yes but most often meditation is done in comfortable (lying/sitting ) posture. The whole idea is to keep our focus on our thoughts while keeping the entire body is at rest. Any stiff postures will result in losing that focus.