we just came back from 2 weeks in Malawi, and here are our recommendations
1. Anake Taxi service if you want to rent a local car/driver - there is poor public transportation so getting a car/driver is pretty important to get to tourism areas. Andrew Bita at Anake will take good care of you.
2. we used AirBnB in Lilongwe and Blantyre and they were great. We travelled with my family (2 adults, 2 teens) and having an entire place was great.
3. We also visited Zomba, Mzuzu, and Manochi. Don't miss any of these places. we also went to Majete park - you can turn up and get a tour guide/car (if you don;t have a 4x4) for $25/person for a 2 hour tour of the park. They also have a lovely restaurant at the park. The drive from Blantyre to the park is gorgeous (through the mountains).
4. Malawi has MASSIVE issues with power and internet. Bring power banks as the power can go out for 8 hours or more if you are not staying in a hotel. The AirBnBs we stayed in all had solar power/inverters and generators as backups, but there were still gaps. Internet is really unreliable (we were on both TNM and AirTel).
5. Malawi has issues with clean water, so carry your own at all times. They also have malaria, especially during the rainy season.