OP I am very rural (and Scottish, married to another Scot). West coast. What follows is not negative. It's what we take for granted. BUT:
Re gas - no mains gas in most of rural Scotland. People have LPG ('Calor') with a big tank that is somewhere easy for the gas tanker to connect to. Often this has to be right in the middle of the front garden. In the garden, deer will eat your roses/veg, unless you put up high fences etc. This can feel a bit like living in a cage.
Most rural properties have no mains drainage. Septic tanks. You'll need to take out quite an expensive contract to have them maintained/unblocked/emptied.
Re food - no supermarket deliveries where I live, and in many other locations. Even in 'hub' towns, Inverness, Oban, Fort William etc, you have to remember that we are right at the end of a long delivery chain. Fruit and veg may have travelled for 48 hrs to get to the store. The supermarkets/wholesalers all do their very best, but we all find that fruit and veg, once purchased, does not have a long life. I have THREE freezers (in an outhouse) and use them all. This with bells on for the islands.
Unless you are in a town, you can't just 'pop to the shops'. Most village stores do a great job, but what they have will be very limited, compared to what's available in many urban centres in Scotland or elswhere. It will also be a lot more expensive. Not because the shopkeepers are profiteering, but because they have to pay more to get supplies. A great many other things - hardware, paint, building maintenance supplies etc - have to be ordered for delivery, or else you have to make a long journey to somwhere like Inverness to get them.
Petrol is also not always easily available - in rural areas, pumps can be few and far between. It is also more expensive than in cities and towns.
Re deliveries - even though the Highlands is on the UK mainland, Parcel Force and most delivery/courier companies pretend that we are offshore, and charge quite a lot more for deliveries. Having said that, local post men and women and local courier company drivers are fantastically helpful. But delivery times are longer, and less predictable.
Telecoms - many areas of the Highlands still don't have 'normal' broadband. Some have slow ADSL; some have very expensive and download-limited satellite (that is affected by the weather). The same applies to TV and radio. Where we live, you can't get BBC Radio for much of the time. For TV, most people have satellite.
Schools - very rural children (even tinies) are routinely bussed quite long distances, for up to an hour each way. Where I live, secondary school pupils have to be weekly or part-weekly boarders. As a result, social life can be difficult for children. As they get older, you will probably spend hours and hours and hours ferrying them around in the car. The roads are not really safe for cycling. Most remote villages - if they are lucky - have one bus per day.
Roads. Single track, mountainous, often ungritted. Slow and (to repeat myself) not safe - corners, cliffs, ditches, odd cambers. Clogged by tourists - camper vans! - in the summer. Blocked by fallen trees etc in stormy weather.
Hospital/GP/Dentist/Ambulance/ Care Homes etc. If you will need these, check out where the local facilities are. Until recently, our GP was an hour away each way and the hospital/dentist 2.5 hours away. It took an ambulance at least an hour to reach people. The only first aid was from volunteers, who were not licensed to prescribe several life-saving medicines.
In the west, it rains an awful lot. Even more than west of the Pennines. The further north you get, the darker it is, evenings and mornings in the winter. The sun set here at just past 4pm today and it was dark, and pouring with rain, and very windy.
I have found neighbours in the places we have lived quite wonderfully kind and helpful. Community feeling really does exist, in my experience, but that does mean that you, too, are expected to play a part - I'm not for a moment suggesting that you wouldn't - and that people will feel that they have a right to know your business and comment on it. The same is true for small communities worldwide, I expect. It's not particularly Scottish. But - as if you were moving into any small community, anywhere - I'd suggest listening carefully and learning before voicing too many opinions.
At the same time, communities are increasingly divided, between local people whose families have lived in the area for generations, and increasing numbers of newcomers (who mostly move from areas where housing is more expensive, and can afford the nicer houses). There is a really serious shortage of affordable housing in many areas. There is also a serious shortage of work for young people to do. In theory, more and more people should be able to work from home. But only where there are decent telecoms...
Crofting is a remarkable institution and has helped generations of Highlanders and their families to survive. (I'm not knocking it; my ancestors were crofters.) But it does involve real differences in land tenure and land use; these can be surprising if you are not used to them. Any Scottish solicitor will explain, however. Local crofters also sometimes tend to form a community within a community - for entirely practical and understandable reasons.
Having said all that - remote parts of Scotland are a fantastic place to live. The scenery. The beaches. The fresh air. The space. The wildlife. The opportunities for outdoor activities. And, in our case, the lovely neighbours.