Strategy meeting house purchase or "How far should I go?"

But that presupposes that the person responsible must be found first. That is a disaster in the company. We have been trying to get someone on board for 2 years :D But well, that shouldn’t be our problem. We have absolutely no time pressure and the longer it drags on, the less interest has to be paid for the interim financing.

Well, if the company is listed as having pre-emptive rights, then everything just has to be verifiably sent to the company (the notary should know the best way to address that). If the company doesn't have its internal processes under control, then that shouldn't be your problem.

But that assumes that the person responsible has to be found first. That is a disaster in the company.

It's quite simple. There are managing directors who act on behalf of the company. They can react, but they don't have to. Not reacting means that after two months the right of first refusal has not been formally exercised and therefore does not apply (at least for this sales case).
With a private person it might be more difficult, but with a company you can sit back and wait for the deadline.

Just a quick update: The offer was officially rejected only after inquiry. I find that quite rude. The ad was also taken down. So either they had other interested parties (which I hardly believe) or he is trying to repost the ad.

I find that rather rude.

He obviously thought the same about your offer and responded accordingly. I would do the same if negotiating isn't even worth it.

We also currently have our house up for sale and do not respond at all to bargain hunter offers with discounts of 20% or more. There are also quite adventurous reasons given as to why the house is supposedly not worth more.

The highlight was: "We are actually looking for an apartment for 400k, but this is a house. For 400k we would take it" ([selling price is 530k]).

It is not rude to ignore such offers. It is simply not worth the time to respond to such offers, as people only want to make bargains anyway and are not willing to move even an inch themselves to maybe reach a price that is acceptable to both sides. I prefer to wait for a buyer with whom one can negotiate seriously.