Best trading demat account?

Finvasia order placement is super smooth. But note their client base is around 30K. So if there is a sudden scaling up of customer base am not sure how good their infrastructure can take this load. But as of now its great.

You have to put in absolute points for Target and SL in Finvasia.

Yes multiple login is possible in Finvasia.
But if you are trading on laptop and once you close the window or you want to open another ‘Shoonya’ (Finvasia trading platform name) window then you have to login again.

Also note this

Can we use same equity capital or margin for commodity derivatives on finvasia or any other brokers ?

You can use equity capital to trade commodity derivatives in Finvasia and Dhan.

How about pledged margin for equity and commodity derivatives?
2. Market order for long-term options ?

You have use cdsl pedging w.r.t 01 august onward. And you will get collateral margin for specific segment you choice from cdsl. Securities/Fund will be pedged seperately for equity/ derivative / commodity. Means if pedged for derivative then you cant use it in equity or commodity.