As far as the Lord leads and direct from His Word and Holy Spirit, once one get that straight you will know how far to go by listening to His voice, when He says Stop, this or that is O.k/Not O.k.
As the Lord says, My sheep hear my voice! So if you belong to Him, you will hear what os too far or not.
The questions to ask regarding how far a Christian model should go when performing is, does it glorify or distract from God. If you knew He was physically go to attend your performance, would you do it? Would you feel comfortable doing it? The fact is, He is there - both publicly and privately. What would you do?