we live in an old (1775-1780) former tavern--see siggie.
Old windows are priceless visually & energy suckers, too.
There are ways to restore windows, retaining the house's unique architectural heritage, while making them much more energy efficient. there are also reproduction windows, shop around, they can get quite pricey & while some are super nice, they may be too much quality for yr job, for instance, we decided against having teak windows & are going for another hardwood--after all, they will be painted out & should last for at least another 50 years!
It is always a temptation--believe me even I am sorely tested here- to go with a 'blow out' after all, it's
much less expensive & research is minimal compared to doing it up faithfully &
monumentally less time consuming!
Yes, I would like a high tech kitchen, but have decided to add on so as not to disturb the great room. We figure we are 5 yrs into a 20 yr project
You have to decide how much of yr house's historical integrity you are willing to sacrifice to accommodate yr living standards. so many people will, for example, pull down plaster & wooden keys, because it is rippled. A restoration plasterer--as OP said, you need to get workmen familiar with old homes--is needed. Often walls have important stencilling beneath layers of paint & those can be saved. We like our rippled walls & ceiling, the wide planked floors with a topography all their own
Contact yr local historical societies, preservation groups for history on yr house & its inhabitants (hopefully, all have gone 'to the light'

) & for tradesmen & craftsfolk who know old houses & are competent to work on them. I also work & volunteer at a museum house & we do this sort of thing, often for
free 
If you decide to gut

still contact them so they may document. They can advise you on what can be salvaged to be sold to yr benefit & make another restorer happy to have it
as I write this, restoration masons are in the great room restoring our main chimney--3 fireplaces, beehive oven--from top of roof (3 stories) down--about $20,000, & that is with DH doing a lot of the tear down himself. since many of the old ballast bricks crumbled into dust as soon as we picked them up, we have spent plenty of hours scouring the state to obtain old brick(the one's we're using are 1750's), pick through, clean it up & transport--
by the by, you can insist that there not be any ghosties in yr home, it can actually be in the contract. I do know of a few other homes that have 'activity' in them
we do plan, if we ever decide to sell our house, to sell it with a HNE-Historic New England--(SPNEA) covenant on it. It will probably mean less money, but it is a way of preserving the history & physical features which make all historical homes, cultural gems.
I often think of what the people who lived here went through--they marched with Gen.John Stark to Bennington, were at Breed's (Bunker)Hill; distinguished themselves in the War of 1812, provided shelter on the Underground Railway,
feared Bristish invasion of NH during the Civil War as well as marching off leaving their families behind. Each morning I put my hand on the original banister, plain, worn to a polish; that hard working women & staunch patriots put their hands upon.
Jean