How do you make formal commands?

Hi, a couple questions here --

1) Formal Commands

-Does one have to use the せconjugation with irregular honorific (sonkeigo) verbs?
For example,
いらっしゃいませ is Correct, but is おいらっしゃりください

-How would one go about making a negative formal command
I know of 〜ないでください, but is there a more stylized way? Are negative commands inherently impolite?

On a similar note, would one use たべないでください or めしあがらないでください or おめしあがらないでください ?

-When being extra formal, instead of ください, is くださいませ functional?

2) Formal adjective conjugations
I know the difference between using ない and ありません and between having a です or not, but is there a specific way to translate adjectives into a comparable-to-honorable tense form?
There are instructions here http://kimallen.sheepdogdesign.net/Japanese/polite.html , but I don't know if they are reliable.

1)
I assume you are talking about formal "requests."
Please consider　いらっしゃいませ as a standing phrase for a shop clerk welcoming someone into the store, it has a formal tone that you would not really use in daily conversation.

Let's say you are seeing off a regular patron from your restaurant, and you want to say please come again, that might be:
また　いらっしゃって　ください
because "irassharu/irasshaimasu" is the sonkeigo verb, you take the te-form and add "kudasai."

Negative requests of the extremely respectful sort... I can come up with:
たべないで　ください　("normal" formal speech)
めしあがらないで　ください (from "meshiagaru/meshiagarimasu)
おめしあがりに　ならないで　ください (o-meshiagari ni naru/narimasu)
おめしあがりに　ならないように　おねがいします (I request you that you would take care so as not to eat...)

The more roundabout the expression, the more polite it is, so it can get longer like this.

くださいませ is usable, but it IS very formal, as in customer - staff relationships.

2)
So you are talking not about the regular informal - polite speech level such as:
あたらしい　vs. あたらしいです
あたらしくない　vs. あたらしくないです

but
あたらしゅう　ございます, the extra polite expression.

I believe this is spoken (as far as I know, and I am a Japanese in my early 50s) only by certain Tokyo people of certain area/upbringing, and I have not used it in my life. Its negative form would be あたらしゅう　ございません.