1) Tumbado is not that much further away
2) Spain has more ports than any other nation to trade from.
3) My stance with this new patch has been to focus less on operating out of the Capital and use another port for most of my business.
4) it might be better to use shallow ships over large traders, I live on a traders brig with rattles for escorts. They are faster and can access more ports, even though they carry less. If I am caught it is less of a loss for me than to carry everything at one. Get capped on an Indiaman and you're gonna have a rough time.
*Disclaimer - this is my play style and my opinions. If you would rather move as much cargo as possible, that's your right. I prefer sailing further for a larger return, only then would I use something like an LGV.