Just tried them and they worked. What does it say? In general what is your fashion advice for interviews?

As above.  While a checked shirt is nothing groundbreaking, there is the very real risk of it drawing an eye that should be on your face.  When they look at you, they remember you.  One can also substitute in a dark gray suit, maybe even a light blue shirt, but traditional, blandly unassuming, and professional is the desired look.
The tie is probably fine unless you find someone ancient enough to associate black with mourning.

Potentially unsafe, hope you dont get blacklisted forever.

Depends on many things, expectations of the interviewers including their prejudices, especially sartorial ones. I made that mistake once, it's well documented, I turned-up for an interview in an Italian suit and the country manager had a t-shirt, sneakers and Casio watch and looked at me and sneered: I was his de facto image of a hoho. Which was particularly annoying as I had already been through three interviews by that stage.

Sartorial issues aside, be wary of this style of interview, it means you're being interviewed by a HR professional(s) who knows nothing of the job and position in hand, your mission is always to avoid them and proceed beyond them to the next level, where you will hopefully be interviewed by someone who wants to see how you will bond on a work's night out:

http://careerservices.wayne.edu/behavioralinterviewinfo.pdf

https://en.wikipedia.org/wiki/Situation,_Task,_Action,_Result

I would say the latter, a little puffy lol. Ben Carson is now beating Trump is some polls.

Not I bet they discuss your outfit on AAAC and give it a thumbs up and then discuss how to stick their thumbs in your suithole.
I mean, you are gay, arent you?
No offense, nowadays that is quite an advantage ,