why do electric field lines not form closed loop?
(1)Electric charges can exists as monopole or positive or negative charges exists independently thus the lines originate from the charges and eventually fades at infinity.
Electric field lines flow from positive to negative charge thus never come back to the positive charge. Therefore they do not form a closed loop. This can be considered as a straight one way road.Whereas magnetic lines form closed loops because they come back at the same pole from which they originate.
(2) Kindly ask seperate questions as seperate query.