some question about my O2 Home S 50 Flex

Sorry, just question 1 and 3 need answers. 

Thank you guys.

With your description in point 2, you have already answered your question in point 1 yourself.

You can use the SIM card in any device of your choice, including a smartphone. However, O2 Home tariffs may only be used at the contractually agreed address of use. This means that the smartphone must remain at the contractually agreed address of use;  you are not permitted to use the Home SIM card anywhere else when you are away from home.

​@blablup  Thank you very much, make sense for question 3, do you know how much do I need to pay if I use it outside of the address? for 1GB?

For question1 do you know the average speed for I am thinking my speed is too slow. And I don’t know how to add an order of the 5G router now as I didn’t order it at the beginning when I request the SIM card.

Please advise, thank you!

The use of the o2 Home SIM card outside the contractually agreed usage address is not permitted.  In the event of a violation of the contract, the SIM card will likely be disabled by o2.

Contact o2 customer service if you would like to rent the o2 Homespot 5G. Please note the prices according to the price list.

Hello ​@jianpeng ,
welcome to our o2 Community 😀
The following values apply to your tariff according to the data sheet 

If you write that the speed on your mobile phone is significantly faster, you already have the answer that it is due to the router. 
Which model are you using? 
Kind regards, 
Solveig