Hakone Free Pass during Golden Week

Hi,
I am in Tokyo from 4th to 6th May. I want to use the Hakone Free Pass within one day. Can I do the whole tour just in one day or is it a problem that there is the Golden Week in Japan?
Does it matter if I go on Saturday, Sunday or Monday?
Are all means of transportation (cable way, boat,...) useable even it is crowded or is it even impossible to use any of them?
Last question: I have got a hotel in Akasaka, Tokyo. Where can I buy the pass best?
Best regards and thanks for your help!
Bene

Can I do the whole tour just in one day or is it a problem that there is the Golden Week in Japan?

There will likely be delays in form of waiting times ahead of the ropeway or buses stuck in traffic jams, but if you leave early in the morning, you should be able to do the loop.

Does it matter if I go on Saturday, Sunday or Monday?

I feel that the traffic jams back out of Hakone are going to be worse on Sunday and Monday than on Saturday, but these things are difficult to predict.

I also recommend avoiding taking a bus in the evenings, unless you prefer stuck in a packed bus in a traffic jam over being squeezed in a train that operates according to the schedule.

Are all means of transportation (cable way, boat,...) useable even it is crowded or is it even impossible to use any of them?

There can be waiting times. But they generally operate on a first-come first-serve basis, so you will be able to ride them.

Last question: I have got a hotel in Akasaka, Tokyo. Where can I buy the pass best?

If you want to travel to Hakone by Odakyu from Shinjuku, you should buy it at the ticket machine in Shinjuku. If you want to travel to Odawara bu some other railway company, then you should buy the pass at a ticket machine at Odawara Station.