Should I edit the edit or what?
No, leave it now, but remember in future.
when there is a tie in numbers like in first case ..should it be 4-methyl or 4-isopropyl ...then winner is isopropyl ...do the numbering so that isopropyl should get 4
That's not how I understand it - in the presence of another side-chain. The rule says "When series of locants containing the same number of terms are compared term by term, that series is "lowest" which contains the lowest number on the occasion of the first difference. This principle is applied irrespective of the nature of the substituents." Thus 4,5,7 beats 4,6,7, so it is 5-butyl-7-isopropyl-4-methyldecane, not 6-butyl-4-isopropyl-7-methyldecane. (And yes, they do accept isopropyl).