Helping the Heiress... again

This riddle is a sequel of sorts to my previous puzzle, the Twelve Zodiac Coins. If you haven't seen that one, I would strongly recommend you take a look at it first.

As a reward for helping the famous heiress, Gwen, solve the mystery of her zodiac coins, you were invited to her mansion. This turned out to be very lucky (for her), because she had yet another puzzle for you to solve. Opening her family vault revealed nothing but a small safe and a printed card with some text on it! Obviously, she turned to you again for help...

"So... you think you can handle this?" she asked.

No, you think, but there's no way you'd say so out loud to Gwen, who thinks you're the greatest puzzle solver since bread came sliced after you helped her out on her birthday. Hoping to distract her, you cast about for something else to say.

She rolls her eyes. "Yes, he gave himself that name in his youth and no one knows why. In fact, he's always saying he can't believe no one has seen the meaning behind it yet."

Well, there goes that topic of small talk, then. Time for another valiant attempt. "He really likes his horoscopes, then? Zodiac coins and all?"

"Yeah, he does. In fact, he tries to live as the personification of his own sign - you know, always trying to be a king, leading the pack..?"

"Uh huh..." Still distracted by the puzzle, you're responding on automatic here when you ask, "So, what about you? You do that too?"

"Well, of course I -" she stops mid-sentence, and when you look up you notice she is blushing. Then the shoe drops, and you blush too. You stare hard at the puzzle while your ears turn red.

She seems eager to change the topic too, and says (a little too enthusiastically), "You know, before I opened this vault, my dad told me that it was a father's duty to lay the foundations for his child. Do you think that is significant?"

"Probably no -" Your brain catches up with your mouth, and you freeze. Of course! It all comes together now! You hastily scribble in your trusty notebook for several minutes while Gwen watches in amazement. Finally done, you look up in triumph.

"I think I know the 5-digit passcode to open this safe now!" You proclaim. Well... do you?

Note: this time, the story contains necessary clues.

• So obviously she's Virgo and her father is Leo. Treating the grid as a wordsearch, I couldn't find LEO or VIRGO anywhere, and the only FYI is way up in the top right corner. Nor is there any SPICA (the only well-known star in Virgo, which I guess "your lucky star" refers to). Commented Sep 23, 2016 at 2:08
• I wondered when you were going to show up. That's a pretty good start! Commented Sep 23, 2016 at 2:22

From the conversation we know that ...

... Gwen is a Virgo and her father is a Leo.

The father's name F.Y.I. ...

... does not mean "For your information"; it is a Caesar encoding of his sign Leo rotated by −6.

With this information ...

... we can look for other signs of the Zodiac encoded in the same manner. It is not easy to look for words like "Muacnnulcom", though, so it is convenient to rotate the search grid by 6 and look for the signs.

The grid then looks like this:

and we can find all signs except Virgo.

We are looking for a five-digit numeric code and ...

... the poem on the card say "Count on your lucky star", or "lucky sign", rather. Count the occurrences of the letters of "Virgo" in the remaining (i.e. unused) letters of the word search and the five-digit combination is:

21995

Edit by OP:

100% correct! If I may point out, this passcode is also Gwen's birthdate, which can be deduced by looking at the date when her birthday puzzle was posted. :)

• Wow, good progress! I'm sure after some thought into the other clues you'll solve it soon. :) Commented Sep 23, 2016 at 7:33
• @Xenocacia: "Count on your lucky star" - I think I have it. :) Commented Sep 23, 2016 at 8:01
• @MOehm: nice, can't wait to see your answer! Commented Sep 23, 2016 at 8:02
• Well done! I edited to flesh out the answer a little, but it is correct. Hope you enjoyed solving it! Commented Sep 23, 2016 at 8:16
• I definitely enjoyed it! It is well-crafted and well-clued. And the additional fact that you just added is really nifty; I hadn't noticed it. (Although it spoils the puzzle a bit for Gwen - wouldn't she try her birthdate on the safe?) Commented Sep 23, 2016 at 8:29