Never heard of a solok fund!.
Congress allows for the withdrawal of funds from qualified retirement plans for specific reasons without paying the 10% penalty and in some cases,tax free.
Since you want to borrow the tuition,you should not be subject to the penalty or taxes unless you fail to repay the loan within 5 years.
You can only have 1 loan outstanding at a time from a retirement plan.
What's a "SoloK" fund? If this is some sort of tax-deferred retirement plan then it depends upon what type of plan it is and what the plan rules are. Loans are possible from a 401(k) plan IF the plan permits them, but not from an IRA. So without knowing what kind of plan we're talking about there's no way to answer your question.
Well that all depends on your specific situation, but in general payments you receive before age 59½ are subject to a 10% penalty tax (in addition to regular tax), unless an exception applies.