Constructing a Suspended Timber Floor

[freddy]

I have a 1930's build house just like the project replacing a timber floor. Is it usual of that type of build to have the joists directly under the wall supporting the doorframes and archatraeves?
I have had my floors replaced and originally the flooring abutted the wall archatraeves and doorframes as the joists ran directly under the wall (just like in the photo on your page), however the builders have dropped the joist height so that the floorboards run under the frames and now all doorframes etc are hanging in the air unsupported.
In addition is a hearth stone usualy level with the joists? I have had two fireplaces removed and the large hearthstone is level with the original joist height rather than the floor height.
The newel post is also sitting directly onto the floor joists as this is the place it is level, is this also usual as I have been told it should be on floorboards however this would unlevel the stairs....
Are these common signatures of this type of build?