can IPA appl'n be rejected due to bad credit score?

Don’t think credit history is checked, unless your home country has a warrant issued against your name and border control stops you from flying out, you should be good.

Work visa/ pass is usually based on candidates credentials, skills, professional background. MoM doesn’t go around checking which bills you didn’t pay.

Credit issues are only a problem if they show up in your criminal record ( and it is checked).