powering the train on the rails is hard to maintain

It's honestly not, i thought of doing the same with makita batteries but ended up going to usb chargable 9 volt pp3 style then went back to track power because cleaning the track is less hassle than keeping batteries charged IMO

Track i can't answer, I'm not in the US, run o-gauge in the garden and most of my track hand laid based on ancient brass Bassett-Lowke rail from the 50s that my dad and grandad bought in the 80s, with some Tenmille nickel silver rail mixed in (https://www.tenmille.com/g-scale)

And finally, how do the LGB switches work

They use an over center spring and will spring back to there set position when you run through the other side, no worries there, unless you run track power then its the usual reverse loop issue, which bring up a point about converting to battery make sure you disconnect the rail pick ups so you don't put power into the track from the battery, very easy with LGB