Permission Denied! for Customer Groups

Hi, Not sure how this has happened and how to fix.

Testing new site before we go live.

1. Checkout fail as 'guest'. We get an 'undefined error' with this showing in the log:

2016-02-01 19:38:45 - PHP Notice: Undefined index: g-recaptcha-response in /home/sites/mysite/public_html/v2/catalog/controller/captcha/google_captcha.php on line 32

At the same time, I noticed there is a mandatory field I don't need to be mandatory. When I turn off google recaptcha, it errors, but one of the mandatory fields does not error out. (if that makes sense). I tried to access the Customer Groups in admin, but I'm getting permission denied. I have checked my admin permissions and they are all ticked!! Happy to go into the DB if need to, if anyone can shed any light?!

This may be all related or all separate.

Thankyou,
Andy

Update to this on the permission denied.

The customer_group is not showing in the modify permission section of the User Group in admin and on the DB, "customer\/customer_group" is missing. Now, I'm assuming I can just add this to the DB, but I'd like to understand why it's not there in the first place?!

Any help from anyone please?! ...

Once I've sorted this, I'll then tackle the Company field in the "guest" checkout and how to stop it from being mandatory.