Can a Self-Emplyed person, who is still working full-time skip thier Pension/IRA RMD (Required Minimum Distribution)?

No. Generally, you must begin taking "required minimum distributions" (RMDs) from your qualified retirement plans and IRAs after you turn age 70 1/2. Then you must continue taking RMDs for each succeeding tax year.
However, you can delay RMDs from qualified plans if you're still working full time and you don't own 5% or more of the company.  There is no such exception for IRAs. Because your Simplified Employee Pension (SEP) is treated as an IRA rather than a qualified plan, you must start taking RMDs after you turn 701/2 whether you are still working or not.

So, remeber: In any event, full-time workers can't postpone RMDs from an IRA.