Log table that grows like flash
Right now we don't know the specification of your "Server" so we can't tell if space might become an issue. 

Apart from that, the answers you are searching for are just a case of interpolating the available data along a time line.

Answering your questions:


From a (MySQL) database perspective: It depends. If the InnoDB page size parameter is set to 4KB then the maximum tablespace size is 16TB. For 8KB page size the tablespace can grow to 32TB. For more information on the limitations of the tables / tablespace / OS limitations visit these links:  


15.8.1.7 Limits on InnoDB Tables (MySQL 8.0 documentation)  
C.10.3 Limits on Table Size (MySQL 8.0 documentation)  

No. Other than observing the limitations of the MySQL specifications. Others before you have stored more data for less interesting cases. 
No. See above.


So space might become an issue depending on your "server" hardware. 

Maintenance

As for maintaining your database, you might want to consider reading the following articles from the MySQL Documents site:


Chapter 7 Backup and Recovery


7.3 Example Backup and Recovery Strategy
7.4 Using mysqldump for Backups

Chapter 8 Optimization


8.5 Optimizing for InnoDB Tables



I guess the worst case would be if you were to lose all your data. Consider performing a simple mysqldump to have a backup of your data. Then consider implementing a backup strategy.