need your help and oppinions

I only plaid warrior and ele and a bit of sin for a short time so i need help from people that plaid other classes (tho some input on warrs and eles are also welcome)

Before i go with the question id like to say i know the benefits of primary profs and how using a 2ndary proff is usually used to support the primary skills

the question is:

What are some great builds that use 2ndary skills in order for the build to work?
(Question for all the classes)

a example would be perma sf sin. Without the 2ndary proff skills that make sf spamable it wouldnt work

you mean like the searing flame ele/me who uses arcane echo?

Yes something like that.

A build that has key 2nd proff skills . Almost making the 2ndary profession more imlortant than the primary.

warrior using necro pleague touch from necro or mending from monk or conjure flame from ele or a necro using a healing circle on his minions si a simple use of 2ndary proffs.

im looking more like that thing with searing flames or a necro using his sr energy managment in order to use monk or rt besling skills and become a nice healer

Physical professions can often run weapons that aren't native to them to reasonable effect. Generally they aren't any more interesting than a necromancer pretending to be a mesmer or whatever though. Some exceptions include critical barrage assassins and spirits strength rits.

Critical barage sins is a perfect example but isnt spirits strenght a rt skil?
I understand it can be a rt that uses his own skill in order to use 2nd proff weapon and attack skills but what im looking for is the other way around.

its kinda difficult to explain

This.
The top offensive builds for Eles, Mesmers, and Necros absolutely require that skill.

I don't see how you discount SS Rits but not Necros using Soul Reaping to be pretend Monks/Mesmers/whatever. SS itself doesn't define the build; it just enables the viable usage of martial weapons, just like soul reaping. A dagger rit plays differently to and adds different things to the team than an axe rit, which plays differently to and adds different things to the team than a spear rit.

Spirit Strength builds are deeply flawed in one way or another like energy. It's why it never caught on.