Two $if functions for the title

This is by far my favorite program and since i recently got a large pile of files to tag i looked into optimizing my actions.
I figured out every wish i have with the information on this forum except for two i couldnt make it work at the end:

I hope you can help with these situations:

  1. Remove the Feat. in every situation in the title:
    Test Ft. Test (Test Remix) --> Test (Test Remix)

I tried it with a regex: \(.+?\) but with no luck to only remove the Feat. part of the title.

  1. Remove the (Instrumental Version) if the album is only instrumentals;
    IF %album% end with (Instrumentals) remove the text (Instrumental Version) in the title;

I came up with this but obviously it is not perfect yet:

Format title
$if($eql($right(%album%,2),(Instrumentals)),$regexp(%title%,\(.+?\),%title%)

Thanks in advance!

TITLE <== $regexp(%TITLE%,'^(.+?)\s+[[({]?(?:ft\.?|feat\.?|featuring)\s+(?:[^][(){}]+)[])}]?(\s+.+)?$','$1$2',1)

TITLE <== $if($eql('(Instrumentals)',$right(%ALBUM%,15)), $replace(%TITLE%,' (Instrumental Version)',),%TITLE%)

DD.20140821.1921.CEST, 20140822.1139.CEST

This has been a great day, the missing piece of my tagging puzzle completed! Thank you very much!