Yes, you'd tthink that'd work!
A short time ago I actually disabled the antispam.php page by renaming it.
I cleared all caches.
I turned off all cacheing options within Dolphin
I had already removed my Akismet key and made the changes you suggested.
In order to redo the changes you suggested I re-enabled the antispam.php page so that I could see the anti spam controls. Now the Akismet page shows as follows:
All the options are in red as disabled: DNS and URI as well as Akismet.
I thought, OK, lets try an article. I added an article as a user and got the refusal to save because of spam message once again. 'sorry it looks as though you are trying to submit spam'
I do not have a spam problem but THIS is a problem as it costs me users and time.
Any ideas?
By the way I am happy to allow paid access to an expert to have a look at what is going wrong and rectify it, before I roll back to 7.0.3 again - which, for me, worked perfectly. ;)