Yes you need a guide because, out off the "beaten paths", it is maze of trails ; besides, a lot of excellent but small homestays are not on the main trails (for example the one of Olivier Sapa) and you will not find them , especially because a lot of them are not even signaled. Finally, many locals speak no English, so, how to you get answers to questions or requests for direction ?

The best agency I know is Nomad Trails, ex-Sapatrek

That's them in both cases. If you can find the Google "sites" page for the hotel there is a bunch of good info there. Hotel should be around $8-$10 no aircon but few places in DaLat have AC because it's at 1500mts elevation so cool enough most days.
You might try going north when you leave DaLat to Buon Ma Thuot (BIG coffee area) and on to Pleiku before heading to HoiAn on the coast. That keeps you inland but you miss Nha Trang beaches. Everyone goes to Nha Trang and few go to BMT and Pleiku so that's your choice, off the beaten track or down The Banna Pancake trail.

Hi,
We had a great trip!
Angola is an awesome country to travel in. Very nice and helpful people and easy public transport. Although transport to sights off the beaten track is pricey, as you need to hire a driver.
We did stay at Residential DB in Luanda, thanks for the advice. It was a good starting point, within walking distance from most places in the city center.
During the two weeks, we made it to Namibe and the Namibe desert, Lubango, Benguela, Kalandula Falls Pedras Negras and the Shipwreck Beach. All very recommendable 
As for budget accommodation, not many places exist on the internet, but in most cities, you can find hotels by walking around town.
We stayed in:
- Diversi Lodge in Namibe: nice, cheap and friendly location right by the beach
- Novo Hotel in Lubango: 3* business hotel at an ok price
- Nancys Guesthouse in Benguela: with Nancy as a very friendly and helpful host
- Hotel do Cacuso in Cacuso: cheap and probably the only place in town
- Hotel Miradouro in N'dalatando: Cheaper than the 5* across the street
- Kwanza Lodge, at the Kwanza River: Beautiful location right at the mouth of the river
- Residential DB in Luanda: Good central location
- Flamingo lodge in the Namibe desert: Great place, far out in the desert, right on the beach
Kind regards,
Jette

Sure,there are a lot of tourists in Bali.There are some places that have few or no tourists even there,but most places of interest/beauty will have tourists.

As Giora mentions there are lots of other possibilities,and all the other islands have fewer tourists than Bali does.Flores maybe combined with Komodo/Rinca is a good suggestion.Labuanbajo is the most touristy town on Flores but even there it is less busy than most of the Balinese hotspots.

If you want even fewer tourists,another possibility would be further east from Flores...Lembata,Alor area.That is pretty well off the beaten track for most westerners.Or Sumba,south of Flores? There really are so many options in Indonesia...

Of course, it's a matter of personal preference. I'm not saying I think Phnom Penh is a nicer city, as I said, it's incredibly dirty but I found the Killing Fields and S21 more interesting than anything in Luang Prabang. When it comes to Hoi An I think it just doesn't live up to the hype. By saying it's not authentic I simply mean that it's more just laid on for tourists as opposed to being off the beaten path so you'll see more tourists than locals.

My first Super Cs (circa 1990)just had 2 drop over hooks, with no locking at all. They did jump off when doing some rough stuff. I used to wrap a bungy round to stop this. https://www.carradice.co.uk/products/accessories/pannier-hooks-4

Carradice then did a strap with a slider at one end that fitted in the alu channel on the pannier and a hook at the other that clipped on the bottom of the rack. This had a tensioner which held the pannier tight and stopped it jumping up. It also acted as an anti sway device.

My latest C's (c2013) have 2 hooks with locking catch. These have never come off. https://www.carradice.co.uk/products/old-man-mountain-racks/carradice-quick-clip-pannier-catches-2

I now see that they now sell the panniers with a combination of the 2 systems. Two simple open hooks and a middle locking one. My locking ones were closed by hand on a ratchet, these new ones seem to be sprung loaded, which are presumably easier, but could fail if the spring goes. https://www.carradice.co.uk/products/accessories/pannier-quick-clip-system

My guess from experience is that if you lock the catch properly, it should work fine. Although if you want, you could replace the 2 hook over clips with locking ones. That should be pretty secure.

Excellent trip report!
I must admit I am quite shocked by the prices and the spread of eco-tourism in many formerly almost totally unvisited areas.
Sounds like thea Punan Tubu have changed little since my visit - dirty beggars full of open sores trying to squeeze whatever they can out of anyone passing through their area, be it a logging company or the odd tourist.

Even with all the eco-tourism development going on, I am pretty sure that your 2 trips still very much qualify as off the beaten track by any standards.
I guess the high prices reflect that the no doubt still few visitors to these areas are mostly on organized tours. Very few backpackers travel this way.