I've only had one fire and that was with lifepo4, and its as violent as li-ion when it goes off. I've been using both li-ion and lifepo4 as house batteries in my van going on 4 years, as long as you don't overcharge them or short them out they are fairly safe. Just make sure you never puncture one, that is guaranteed to cause a fire everytime.
Always use an overvoltage protection relay to disconnect the power source/solar panel as a deadman switch. Use some sort of overvoltage/undervoltage audio alarm on your battery also. The only bms I recommend is one that uses contactors (to mechanically disconnect the power source or solar panel) , I use the chargery bms8 for that reason its never let me down and you can quickly program on the lcd screenwhat voltage you want the power to disconnect at. The chargerybms8 works with any cells li-ion or lifepo4 up to 8s, they also have 16s model for larger packs.
And for building the pack I would do it right the first time and get a 12 volt tab welder, the best tool I ever bought for building battery packs, gets you a good professional job everytime, the reason I got the 12 volt tab welder was cost and also to build the packs inside my van. The first couple of pack I built I solder and that was very time consuming. I use the maletrics welder (cost in 100 dollar range) and it makes quick work of the job. Double check all your wiring especially the balance wires. Use as many fuses as you need, you can never have too many fuses.
Right now inside my van I have a 220ah 4s lifepo4, 2x 30ah 3s lion, 1x 65ah 3s li-ion, another 30 ah 4s lifepo4, 4x 10ah 4s lifepo4 jump packs, and I even keep a 28ah agm lead acid battery to run my tab welder and as a spare engine start battery.
The only fire I had was due to complacency, I was taking a lifepo4 pack apart and I shorted out a cell which punched a hole inthe side, I heard lifepo4 was a safer cell so I was rushing, I learned the hard way that lifepo4 is as dangerous as any other lithium when mistreated.
Over the years I was more scared of my propane heater catching my van on fire then my lithium batteries, I got rid of propane heater.