Good Morning Vad,
I'll do my best, I'm sure Darrell will read this and clarify it for you further if needed...
1) Ideally you want there to be enough of a distance between the izones that your scalp has a chance for success. Depending on the instrument you are trading most scalps are for 10 or 15 ticks, could be more but generally that is where it starts. If you are entering 3 ticks above/below your signal bar then you want to make sure that there is enough distance from the beginning of the next izone to cover that. This is where knowing your market will help, no two trading days are the same and two markets are the same so you have to get the bigger picture for your market for that day to judge if scalping between izones is a good option. For me, I look for enough room to grab at least 15 ticks from my entry point to the beginning of the opposing izone or I don't generally do the scalp unless volume is really exceeding.
2) For a trend trade you want everything to line up and you want the MVP to flip by the 3rd or 4th bar after the cyan arrow. That was the general rule of thumb with the Trend catcher system and I'm not aware of any changes to that rule. Again, look at the bigger picture of what the market is telling you and judge from there.
3) When scalping, I generally look for TC, Trend Flip and trend bands to line up and green izone for a long scalp or a red izone for a short scalp, I don't necessarily look for the bar trend/chop filter colors to line up but I do look at the direction that the bar is closing (If my signal bar is closing down, I'm not going to enter a long scalp, or if my signal bar is closing up, I'm not going to enter a short scalp).
Now, keep in mind the tools and rules that Darrell provides us with are a guide to get us started, but what I do that works for me might not necessarily work for anyone else, you have to apply your own style that suits you. Know what your market is doing on any particular day and adjust your trading style to work within those parameters. I follow the rules of the system, but I adjust for what the market is doing on any given day. The best way to describe it is as Darrell often states in his video's, he gives you the A B C's of the system, you have to figure out the 1 2 3's to make it work for you. He doesn't know your risk tolerance, account size, trading psychology, etc, that you have to figure out for yourself and it is just as important if not more so than the A B C's of the system.
I hope this was helpful.