Maximum retention period length is 10 years, which I believe is fairly close to infinite. The FSDB size will grow linearly over time, simply do the math for expected size - i.e. if you current FSDB size is 1GB over 14 days, it will be about 26 GB over 1 year and so on.
For looking into past data I recommend to use absolute time period and specify date/time range accordingly.
Compress data and log files is related to SQL DB maintenance. Since the latest NTA doesn't use SQL much, you can ignore that setting.