I am looking for advice for renovating a 1900 (1905, I believe) Mississippi farmhouse. The original part of the house is to the right and there is 2 story addition on left from early 1980s. My tentative idea is to have a porch on left addition with same roofline as porch on original house in hopes this will pull together....? Advice on windows? (Pics 1-3)

Pic 3 is of original house, 2nd porch with original formal entry. I've considered wrapping porch floor around to join the two.

I'd like advice on how to stay true to the time period on exterior (the porches have almost Victorian look with posts).
Also hoping for some ideas on how to open up interior for more open feeling as all rooms are 12x12 or 12x15 with 10' ceilings, small hallways and bathrooms.

The home will be essentially for 2 families - mother in law wing upstairs using door shown on addition and a 2 story deck built at end of addition (not visible from front- see pic 4) and use original house for family of 3. I'm trying to keep 2 entrances for privacy (so my 3 year old doesn't drive my Mom crazy with noise!).

Recommendations also requested for websites, blogs and photo sources (lighting, floors, everything!).
Thanks!!