In answer to your first question, my advice based on what you have told us is to continue to serve her: serve her liberal portions of spanking and having your way with her when she is tied up. You are then Dominating by deciding to do what you want to do and she is submitting by acquiescing to your desires.

As for having a problem that you want to please her - that isn't a problem. The best D/s relationships (like the best vanilla ones) are where there is deep love between the two of you. Speak to many Masters on this site and you will find that they adore their sub to bits and strive to make sure they are happy. (Of course we are all human beings often with work pressures etc. which mean that's not always possible but the intention is there). Spanking and bondage are exactly what she wants so that must mean you are pleasing her, which is another thing that you have decided you want to do.

Being a Dom means accepting the gift of control that a sub gives you. How you use that gift is up to you. Most advisors would tell you than you must hold on to those reins of control firmly in order to please your sub - interpret that as you will, because another well-quoted adage is that every bdsm relationship is different.

If you want further advice outside this forum you and/or your wife may message me via YIM.

VV