My most recent submitted run was verified but due to capture card delay it looks like I'm starting and ending time 1 second early. I know since my time is so low it probably wasn't a problem or there is some leniency there but would this eventually be a problem for me getting my runs verified when I submit faster times?

1. no, the verifiers retime every run
2. if you want it to sync with gameplay just add render delays or delay hotkeys in settings

The timer shown on your stream doesn't matter at all to verification. I submitted PBs like that for years.