Having limits and boundaries does not mean you are not willing to test them or push them later on in the relationship; it is a way for your partner to learn more about you. They will pick up on your reactions, the sounds you make, and how your body moves during specific activities or scenes. It is all about the subtle clues, and with time push past boundaries and limits.
Subspace is something that many submissives compare to an out-of-body experience or being lost in a world of bliss inside your head.
When you meet a Dom or sub, and they think safewords are not necessary, run like hell. This is a huge red flag from the get-go and something you should not even consider exploring. There are too many people claiming that safewords aren’t needed; these people don’t understand BDSM and definitely don’t have your best interests at heart.