is it bad if i do 25 reps with light weight, 2nd set doing 20 then 3rd 15reps if i'm toning up?

To tone up, you still need resistance. If you can do 25 reps, then you do not have enough resistance. You should use a weight heavy enough that you can only do 10 - 12 reps before burnout. The workout you describe is just a warm up heavier lifting, but won't do much for toning your muscle. Many people buy into the myth that doing massive reps at a really light weight will result in tone muscles, but if that were true then I could tone my muscle by lifting my water bottle all day long.

Nope for toning up you will need more reps compared to weight. What you are doing is right.

You only need heavy weights if you are trying to build big muscles

Toning = Light weight High reps (like 30, 25,and so on or more)

Muscle building = Heavy weight and Low Reps (like 15, 10 reps with heavy weight)

i would try it the other way round 15, 20 then 25

Most pyramiding is done the way you describe to warm up muscles before heavy weights are lifted, with this amount it shouldnt matter as much and you'll get a better burn, which is always good.

No it isn't bad, you will want to do many reps with a small amount of weight. That will build endurance, not muscle mass, which is what you're after for "toning"

That sounds like a very energetic routine and a good one. Since you are noticing tone and you are not experiencing any pain that goes beyond mild soreness then continue on with it because it is a good routine for you and you are making gains with it. I admire your commitment. Good luck with it.

nope. wight training is done best in reps and if you choose to do them that way, it's fine. At least you're doing them

Not at all. That is exactly what you should be doing.