No. iTel S41 does not have a hybrid sim slot. It has 1 dedicated slot for MicroSD card and 2 dedicated sim card slots.
iTel S41 dimensions are 144 x 72.4 x 8.3 mm.
Yes, iTel S41 does have VoLTE support.
Yes, It does have.
Yes, iTel S41 runs on the latest Android 7.0 and thus having support for the multi windows operations.