Hi sfo1, sorry to hear of your predicament and I will try to answer as best I can. Some of your issues I have knowledge and personal experience of, others I dont and Im sure someone will better knowledge than I can answer those ones.
Hacienda, as soon as monies hit your account, will hold them to pay for whatever is outstanding, and they will keep doing that until all debts are paid off. I cant see them leaving a 2 year grace as they automatically send out embargoes for monies owing. Maybe there is a way you can get around this but I dont know for sure. Best thing to do is not put any money into your account and indeed close them down (the company ones). I suspect the 2 year grace works as you try to pay them when you can but directly into their account, or maybe they have to agree a payement schedule which would be signed and maybe notarized, that I cannot answer.
The SL is like the LTD company in as much as the company is liable only for the amount of capital, usually 3000 euros, BUT the administrator is personally liable for debts especially if they are seen in a way where you are trying to avoid payments, and certainly in the cases of tax and social security payments! Any assets in the name of the administrator will be targetted!
Re the proeprty you can request an up to date nota simple - your lawyer can do this and its a cost of around 12 euros, this will show any embargoes on the proeprty. If they are there then when you sell these have to be cleared in order to pass clear title to the buyer. Same as for cars, bikes in fact anything with the administraotrs name on.
You could change the car title into your name if its clear to save that but you will pay for the transfer. Re the house if youhave a mortgage then probably you will have no choice but to see what happens. Again, a gestor will be able to tell you if any embargoes have been placed on any assets.
Hacienda are very powerful and most of the time no one even knows they have placed an embargo - there is no paperwork delivered to you.
I hope it all works out.