I'd prefer to add a fourth option. Go IMMEDIATELY to my supervisor and say something along the lines of, "You asked me to look at this. Mummy always told me never to leave 'strict' out, but my guess is that it would mean a complete rewrite, taking x months. Do you want me to do that, and if so, when?" This means that the supervisor is in a position to balance resources and projects, which is what I would expect a supervisor to be there for. The answer might tell you a lot of things, for example,

"Bleep off & mind your own bleeping business": this is good advice to follow. Another employer should be sought ASAP!

"What's strict?": you have an opening to become the indispensible perl guru in this firm.

"We can't afford the time": it'll be more expensive later.

Granted, I'm a beancounter, but I do seem to spend a lot of time on computer projects. Even in the beancounting world, the general approach is appropriate. Tell the man who makes the decisions what you think should be done and what resources it will require. Then let him do his job and decide. If you're worried about CYA, put it in writing. But I don't like 1 or 3, because you are keeping quiet about something other people need to know, and I don't like 2, because you are criticising other people's work, and they won't like it. You are painting a target on yourself.

One final point, & I'll shut up. Always over-estimate the resources you will need. Not wildly, but leave a margin for things to go wrong. They will!