Trying to get an understanding of how it might feel to live in Nica

Well, that is a lot of questions requiring long answers. First, speaking for the Granada area, we have a lot of single female expats and they seem to be doing well. If you use FaceBook - Expats of Granada is very active. And few expats live in gated communities though they have their advantages. So no problem with social isolation assuming you get along with people. Many of the expats work with the many foundations here to help education, medical, libraries, community centers, women, children and much more. No problem keeping active.

There are many cooler areas. If you live near Esteli, Matagalpa or Jinotega it much cooler but fewer expats. But there are areas near Granada and Managua that are much cooler yet close enough to enjoy the amenities of Granada and Managua. We just moved outside of Granada and it is much breezier and nights are much cooler.

Regards

Darrell

Bushamy is right. Less expats in estelli, jinotega, and matagalpa, but the weather is much cooler there and the wind is blowing constantly when u get up in the higher elevations.
Don't worry about fitting into a community. They will love u. I meet new Americans here every week. Lots of groups coming through now as well. The rainy season is over now and people are starting to come back down.
Medical care is another thing. Pharmacies here have everything u need cheap. I can walk right into a pharmacy and get whatever I need. The meds here work awesome as well. About two months ago I had a cold and runny nose. I walked into a pharmacy and told the girl. She gave me a nasal inhaler and I laughed out Loud at her. I bought it any way for about $2. I took it home and used it and within 15 mins felt 100% better. Worked like a  miracle. Over the years I have gotten sick here on occasion and they always have something that works quick. I go to a dentist here and the price for a filing is around $20. In NYC it's about 2k but that's nyc.  You can find and afford a private dr to treat you for whatever. I have one and a private eye dr as well. I scratched my eye last week and paid $20 for a visit and then another $5 for the rx drops.  People are very friendly and you will meet expats and or locals easily.
Necessities include
1. Patience
2. Open mind
3. Good cookbook
4. Some type of music device that plays music u like, ie iPad, Walkman etc
5.  Good towel. Hard to find a big towel here.
6. Baby wipes as you can't flush paper down the toilet
7. Tootsie rolls
8. Thermal water bottle
9. Hair gel, they only sell one kind here
10. Really great walking shoes.
If I had to prioritize this list I would put tootsie rolls first. Chocolate u can buy here is snickers, twix, and a Hersey bar.  Everything else is almost non existent. They do have M&M but this is hardly considered chocolate.
If you get pulled over by police, a $4 tip buys your innocence. Hope this helps.
One last tip, don't pet dogs here ever! Little ones bite much more than the big ones. I always have a water bottle to spray them just to be on the side of caution.

There are many decent medical facilities in the Managua area.   We would need more specific information on what type of care you would need to provide specific recommendations.

The other posts pointed out cities that are cooler.  If you're interested in the Managua area, but want cooler temperatures, you might want to look at the area going from Managua to El Crucero where the temperature is cool and the city would only be 20 minutes down the hill.  Also if you go near the Barcelo Managua hotel and continue up that hill, it's fairly cool to a point you won't even need air conditioning at night.