I dont know the particular LoRa module you linked too.
Over here in the UK we have been using the bare modules, Hope RFM98 mainly, I have been using the DRF1278F recently as well.
For these modules, using 62.5 Khz and SF8 is becoming the norm, just no need to go to a lower data rate. There was a LoRa flight round by me last weekend (RFM95 on 868Mhz) it was tracked up to 30,000M + quite reliably by a station some 200km away.
If you cannot get your LoRa modules to communicate, there is something wrong with your code or the modules. The crystals could be out, but that is not difficult to measure. On most of my tracker programs, I get the LoRa device to output a FM tone at startup you can use this to measure the output frequency and apply a correction factor if need be.
As for pictures, remember that LoRa is packetised, so you can set it up for high rate, 37.5Kbits max, transmit the picture in blocks then send up a request to re-transmit missing blocks.
And this is where LoRa shines, in one simple and cheap module you can go from a very low data rate of 50bps all the way up to 37.5Kbits. The low data rates provide a stunning ground range and huge potential for locating lost stuff like balloons or RC models, see this article for example;
Tricks such as the LoRa relay are just not practical for other 'primary' radios, due to weight and cost.