I agree with you - most functions in QB online are difficult and time consuming.  I have figured out how to print a chart of accounts in the online version in numerical order.  Here's how - 

Click the gear icon

Select chart of accounts

Just to the left of new account, click run report

Hit switch to classic view just to the left of more actions/export print/ save as

This should put them in numerical order and then you can filter for columns or just print.

If you just want to renumber them - 

Click on the gear icon

Chart of Accounts

click on the arrow next to number 

This should do it.  If it doesn't, chalk it up to another disappointing feature of QB online.