STOP PAYING FOR THAT SUBSCRIPTION!
1) First of all, fully authorized and legitimate bios updates should be available from your PC manufacturer's website. Use those, IF REQUIRED, not ones from a 3rd party website.
2) Bios updates do not prolong your computer's life. They may simply resolve a problem or provide a new beneficial feature. If you never update the bios in the computer's lifetime and dont experience any issues (as you said), you'll be just fine.
3) Flashing the bios can be risky! It has the potential to brick your motherboard if you dont do it right. also, the most important thing to do before flashing a bios is to be prepared for a bad flash. How? having a bootable usb/cd with a working bios ready and being fully conversant with the recovery procedures. A lot of people dont take that basic precaution and get bombed.
Nobody can say with 100% guarantee that a bios flash will succeed. That way computers can be most temperamental (like cats).
So:
1) Research your bios update options at Toshiba's website.
2) If you discover a bios update for your model, go through its CHANGELOG. That'll tell you what it brings to the table.
3) If you see something desirable, take ADEQUATE PRECAUTIONS that I mentioned and then proceed.
Otherwise, sit tight, watch TV and have a beer! Your computer will be fine.