muscle growth makes you heavier.

No such thing as lean mucle, what you want is lean body. Lean bpdy is achieve by having low body fat.

So your program should be focus on losing fat. While reserving muscle as much as possible.

Cardio and hiit will be your main menu, but your appetizer should be moderate heavy lifting. By lifting heavy first your body will use the stored glycogen as energy source, after you get somewhat tired and weaker(depleted glycogen) then you proceed to your cardio so that your body will start using body fat as fuel.

But exercise is only the tip of the iceberg
The major "work" on losing weight should be checking your diet, count your calories and consume less than you need, not want.

You mentioned you are not losing weight LATELY, I assume you had lose some weight before and now stuck at your weight. Its normal as you will experience fat lose getting harder and harder as you losing more weight. Because now your body has adapt to the diet and exercises you did, so you will haveto rempt it up by exercising harder and consume even lesser. Until you have reach your desired weight.

1 hour is a lot, 30 mins is suffice exclude your warm up. Then 30 to 45 mins of cardio.

Cardio doesn't have to be boring, you can do some rowing, swimming, kick boxing, basketball, football or any sports you like.

It all depends on your goal

If you want to focus on fat loss then its better to do cardio straight after weight session.

If your goal is to improve performance then do them seperate.

What's your height?