Adding overhead lighting and getting rid of half switched outlets
Changing wiring to the extent that you are talking about is a doable project but if you know nothing about wiring or are any bit concerned about feeling safe working with AC mains power it may be best to call in a professional electrician.

Some notes.

Adding ceiling lights to rooms that do not have them is easiest and most feasible if there is attic access above the rooms. Access to the attic allows one to get up there to place decent blocking between ceiling joists to which the electrical box can be secured. This is especially important when you want to support the weight of a ceiling fan from the electrical box. It is also possible to route the wires over to the top of the wall section where the switch is located and drill a hole down into the below stud cavity to poke the light wire down to the switch.

Adding switched lights to the ceiling of a first floor room that has joists above and then living space above that is a more invasive job. This generally requires opening up multiple holes in the drywall or plaster walls. Obviously the wall materials can be restored but it adds lots of work and the need to repaint the room afterwards. Access holes in ceilings that are textured adds an additional challenge in the restoration process. I have done this type of project many times and can say it is doable but be prepared for many hours of work.

Your '70s style house may not have vaulted ceilings but if you so in your dining / front room it may be a challenge to gain overhead access. Vaulted ceilings are very often built up as part of a roof truss construction and it is very likely that there is a possibility of no "attic" type access from above. So for this type of room you are looking at the much more invasive type construction work. If adding the switch for the chandelier is intended to allow controlling the light from two locations it will be necessary to run new wires all way between the existing switch location and the new switch.

Changing the half switched outlets to non-switched outlets is most easily done at the switch location by removing the two wires off the switch and then joining those two wires with a wire nut and pushing it to the back of the switch electrical box.

Another consideration is the size of the boxes where the re-dutied switches are located. There are code requirements on just how many wires can be in a given sized box and adding a wire from a new ceiling light fixture could exceed the box capacity.