Yeah, you can't really turn with trikes. I also have a trike, it was a few days till i re-learned how to ride it, i always turned at 20+km/h and had one wheel up in the air, and i had to balance myself, it's kind of fun, but really, turning is not easy at speed.
I've been working on it for 3 days....... I'm ready to take the cutting torch to it .
I've been trying to get the back rim hubs off the axle and they just won't move after being heated to red hot.
I'm at my wits end = take it back to the woods
If you cant get it off the axle then cut the whole assembly off. Use pillow blocks and steel rod instead of the axle if you must....
But maybe try a gear puller or some sort of hydraulic contraption.... Maybe try removing the rust and loosen it up by leaving it overnight in hydrochloric acid or spray bunch of it on and idk... Heating will help a bit, but realize the coefficient of thermal expansion of steel is 7 x 10^-6 per degree C... Which is not a lot but coupled with a bunch of other stuff will help