We're two 70 year olds planning to explore Thailand using home exchange (HE) and booking.com for 5 weeks. So far we're thinking arrive Bangkok for 4 nights, Hua Hin 2 weeks (HE), Pattaya 1 week, Phuket 6 nights (HE), and Krabi 4 nights. We're then moving on to Malaysia for 2 weeks (HE).
We want some beach time, more local culture, lots of great local food and would really welcome your thoughts on this itinerary and the best ways to travel from place to place. Happy to use local transport and hire a car. Thanks a lot

For short distances I use a tuk tuk. A bit farther, taxis. For longer distances buses between towns, long distance fly. I’d discourage you from driving yourselves.

Regarding where & for how long, I think you’re short-changing Bangkok. It’s a unique urban experience that I suggest you give at very least a week. There are several of my Bangkok stories here, along with some Malaysia that might interest you:

https://www.travelgumbo.com/blog/por...l-to-asia-tour

I doubt you will find too much "local culture" in Hua Hin and Pattaya. The former being a major retirement hub for expats from Northern Europe and the latter is widely regarded as the centre of the Thai sex industry. i would give both places a miss. Beaches there are ok but there are better in both Thailand and Malaysia ( the beaches in Phuket & Krabi are excellent) .

Getting around depends upon where you are. In Bangkok I tend to use the BTS sky train and river boats where possible. Taxis and tuk tusk have always been very keen to overcharge tourists, these days apps like Grab are the way to go. There are fixed price taxis form both airports. Flights for longer distances can be cost effective, esp budget airlines like Air Asia. I would avoid buses for longer distances if at all possible due to safety issues. Driving in Thailand is surprisingly easy so we generally rent a car if travelling throughout the country though they are next to useless within cities. Driving in Malaysia is even easier. On some routes , train travel can be viable for longer journey. Check out www.seat61.come for details . It is a nice trip by train from Bangkok ( or even Phuket , via Surat Thani ) to KL

Thanks for all your help and information, much appreciated