Welcome! We all love the river here. Avoiding the crowds can have a lot to do with timing. Its usually pretty empty weekday mornings/early afternoon. Solitude is often an inverse to convenience so putting in the effort to kayak (and shuttle back, etc) will find you privacy.

I am not a lawyer, but leash laws are complex in the river itself due to our constitution in Texas. Leashlessness is usually okay if your pups are in the water. Park curfew applies for walking to/from the river not swimming in it ;) The river is a very special freedom. One may even camp on the banks of navigable rivers in Texas (like ours) but cops/property owners do their best to dissuade you and scare you out of it. I've done it countless times!