candle bar ia also a indicator of mkt price action(ZT)

well, OK. Too much flexibility may concern some traders. Well, I remember the same kind of concerns regarding decimalization.

I'd like to remind you something though.
candle bars are NOT the reality of the market. (I would argue there is no 'single reality' but that's another topic).
the candles 1, 5 15mn or whatever are only a representation of the price action. it does not matter what size you go for, the market action DOES NOT CHANGE because you select 5mn or 30mn bars !

However, it will make a difference on your decision. So that means it's a filter.
Filtering is good to help you make decisions.
Filtering is bad because you may miss important information.

Straight to the point, changing the filter won't show you a trend early. It may filter some trends and help you focus on one.

tweaking the bars might be interesting, it's comparable to changing parameters of an indicator. the bars are an indicator !
and just like any indicator this is in no way a recipe to easier profits, sorry. thinking about it that way is, again, seeking for the holy grail.

the closest chart to 'reality' is the tick chart. if you want to understand how the market works, follow in realtime a tick chart of the nasdaq futures (or ES whatever).
After a while you should get it.

Don't get me wrong I do use bars too, not tick charts. But it's not the most important thing. it's just a filter. and you want to filter because you can't trade all the active trends in a market at any given time. filtering helps you focus on one. don't make a big deal about it.
worse, you may overoptimize your view for a particular market condition and be off when another condition comes in.

of course, if you use the flexibility and remain flexible, then you can do whatever you want.
once you understand indicators (including bars) are not the most important thing.

tntneo