1st: there werent alot of guns, in new vegas they added some but there were still missing lots of bad ass guns. maby add more gunz and but a better aim on them.
2nd: on new vegas the civilisation started to rebuild it self and i think it took off the badass feeling you had in fallout 3 while you were walking in the waste land. so maby make fallout 4 as much apocaliptic than the 3 .
3rd : they were not alot of big city in fallout 3 or new vegas , in new vegas half of the city out side new vegas were destroyed by legion and in fallout 3 they were mabyy4 good city and all the other were house on the road
4th: i think fallout4 need more good looking armor, in new vegas the nicest armor were in dlc.
so how would you shape fallout 4 ?