Floor Joist Under Load Bearing Wall

After incomplete advise by a contractor on how to tell if a wall is load bearing i started tearing out all of the plaster walls realized the wall is load bearing.
Floor joist under load bearing wall. Therefore joists may run from wall to wall wall to beam or beam to beam depending on the size of the area they span and the structural design of the home. For better performance the designer may wish to add a joist or blocking panels below the non bearing wall. But in the past it had been necessary to install a staircase to these rooms above. Score 1 for being load bearing.
This meant cutting a hole in the joists and installing a trimmer joist 1 on. Generally when the wall in question runs parallel to the floor joists above it is not a load bearing wall but if the wall runs perpendicular at a 90 degree angle to the joists there is a good chance that it is load bearing. The space i am opening is a little under 8. Makes the plumbers and electricians smile.
Score 1 for being non load bearing. Thus for a 2x4 bearing wall two joists are below spaced 3 1 2 apart directly under. This verification can be achieved with our forte software. This wall is running parallel to the floor joists above see picture 4.
When i draw plans i locate joists under bearing walls only for parallel walls off layout but i do it with two joists spaced apart the depth of wallplates above. The living room dining room is open concept and the kitchen is walled off. Nonetheless this does not ensure good floor performance. Load bearing walls and floor joist spans how not to knock down a load bearing wall.
When doubled fj s are under a non load bearing wall to eliminate the floor flex that creates a drywall crack above a door header on the wall above typically between a bedroom and master bath. Is the wall parallel or perpendicular to joists. However the floor joists must also be adequate to support the additional load from the wall. But for nonbearing walls why do any extra joists at all.
Common sense tells you that large floor joists can carry more load and spacing joists closer together also increases the load bearing capacity of a floor. But larger is not always better when builders are constructing a home or adding a room addition. However there is a large double 2x10 header above the entry way see picture 4 in this wall supported by a jack stud on either end see picture 5. The joists span across a room or other area are supported on their ends and sometimes in their middles by load bearing walls or beams.