No. Canon firmware is a .fir file. Any .exe claiming to be 500D firmware is almost certainly malware.
Here is helpful, safe, and practical content regarding the . canon 500d firmware 1.1 1 download
No. That limit is hardware/heat-related. Third-party “Magic Lantern” firmware (unsupported, voids warranty) can remove it, but that is not the official 1.1.1 update. voids warranty) can remove it