Unlooted Invasion

Question

I suspect someone broke into my house last night. Nothing was stolen of course, I would have went to the police otherwise.

The reason for my suspicion is a note that I found just beside the door. There were only few people who could get into my house, though I have restricted them to do so! The maid Margret, my girlfriend Aaliyah and the house owner Chester. I am sure Chester has kept duplicate keys for the house to himself, Margret and Aaliyah always have the keys. but I am still not sure if anyone of them or someone else broke into my house.

I have attached the message here.

Rgffvvoi Cgdxz Hf Ahjy Gvqmhug Auyt Lnvt Xyze Hinas Iope Aipta Yuew Gagp

Also my notebook seemed to be misplaced on the table, it was kept open like someone checked it in a hurry and left it open there. There was also a note written on the page, a riddle of some kind, which I am sure I did not write.

Crucial advice in a Sequence of prominent,
Extract the components, only the dominant,

Unravel the tangle with a Glass in Hand,
Then offer Once "a single grain from the desert of sand".

I tried to crack what all this might mean, no luck so far. Maybe you can help me figure out the message?

Also I strongly feel they might have left the clue for me to know who it was. (this can be considered as a hint, if you have found the name already)

Hint 1:

The occurrence of the name in in the note has a particular order.

Hint 2:

The order in Hint 1 is somehow not related to the first half of the riddle.

Hint 3:

The Capital letters in riddle provide hints for solving steps and the cipher.

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_{This is my first attempt at creating a puzzle. I would love to get feedback to improve my next puzzles.}

Answer 1

So far I have caught four things here:

1.

Dominant means Capital letters of the cipher - RCHAGALXHIAYG (length = 13) - something relating to rot13 cipher technique

2.

If we leave the letters of Name "AALIYAH" here, we get fibonacci sequence from the index of the remaining letters - (R, C, H, G, X, G) -> (1, 2, 3, 5, 8, 13)

3.

CSEUGHTO - all the capital letters in the note in your notebook is an anagram for -> "HUGE COST"

4.

Glass in Hand and "a single grain from the desert of sand" might have something to do with time or hour-glass.

I am yet to connect these dots.

Answer 2

I think the author is

Aaliyah, since you can find her name in the capital letters of the note

Answer 3

According to me as mentioned by @SteveV

Aaliyah is the person because her name appears in the note.

So I did the following:

Substituted numbers for the capital alphabets in order of their appearance in the note.

And then I got the following:

471013151412

I am stuck here unless maybe:

471013151412 is some kind of a phone number

Answer 4

Partial:

In the note we find the capital letters CSEUGHTO. These can be unscrambled to get the word TOUCHES.

EDIT: I just realized I missed a G in my word scramble so the rest of this may be meaningless.

As @SteveV noted:

The letters for Aaliyah's name appear in the initial word scramble. Using "touches" as a hint, I took all the letters that touch the letters from Aaliyah's (taking them in order when letters were repeated) to get the letters hunouii.

I noticed that:

All these letters are in the Hawaiian alphabet, so I translated hunouii from Hawaiian to English to get hunter.

Not sure what to do next.