You'll have 30 days to find a place to stay, open a bank account and transfer the money. That's imo enough time (you can do it in less than 10 days). Going for an Elite visa is pure stupidity.
The Elite visa is designed for people younger than 50. Thats why it exists. Now, those people can instead apply for the DTV and not paying for it ,which means much less applications for the Elite visa. Why apply for the LTR as a retiree?
Well, find another "lawyer friend". There will always be rumours and gossip about visas among "lawyers" and agents.The Bronze Elite visa might not survive due to the DTV. The cheapest Elite earlier cost 900k, the Bronze at the moment 650k.
Il est préférable de déposer votre demande dans votre pays. Cela facilitera grandement les démarches à votre arrivée. Vous n'aurez pas besoin de vol de retour ni de correspondance si vous arrivez avec un visa non-O de 90 jours.
You submit a TM30 at immigration, it's an address registration. Your address. You'll get a TM30-receipt to keep in your passport. Now you can apply for the residence certificate.
Like I said, (if you have a place to stay) you should get a residence certificate from immigration. But to get that you need to submit a TM30 at immigration.