How to reach Regal Oriental hotel at San Po Rd from Hong Kong Airport?

Here is what I know to your questions one by one:
1. Comparatively, airport shuttle bus is more convenient.
2. You can take bus no. E23 or A22 and get off at Regal Oriental Hotel, Prince Edward Road East directly.
3. By bus no. A22, you can get off at the 12th stop.
4. Bus no. E23 costs 18HKD and takes about 85min. While bus no. A22 takes about 50min and costs 39HKD.
5. There is some space on the bus to put your single luggage. Don't worry!
6. Generally, as long as your luggage is not too large, it is allowed to be taken onboard.
7-9. By train, I suggest you take Airport Express Train to Kowloon Station first, where you can take the free shuttle bus no. K3 to reach Regal Kowloon Hotel. Then at the hotel, there are frequent hotel shuttle bus to your hotel. The fare for the Express Train is 90HKD per person. And as I know, the hotel shuttle bus needs to be booked in advance, so I suggest you dail your hotel to ask about the details,
Hope help!