A Portkey to more Portkey theory

[ladyofmisrule2000]

No: HPFGUIDX 53262

I realize there are plenty of theories out there as to why Barty
Crouch, Jr. turns the Triwizard Cup into a Portkey as opposed to
transforming something Harry would use on a daily basis, like his
toothbrush.

After all, why go through the hassle of a Tournament if it's not
necessary?

But I had some questions about the ramifications of a couple of these
theories...

Theory one: Crouch uses the Cup because the Hogwart's staff might
assume Harry was killed in the course of completing the maze; thus
masking Crouch's role in the murder and allowing him to go on his
malevolent way.

Questions regarding theory one: What do you suppose was the next step
in Crouch's plan? Sneek out and return to Voldemort? Continue on at
Hogwarts and spy on the professors? Arrange a horrible demise for Ron
or Hermione?

Theory two: Whoever came up with the idea to transform the Cup wanted
Harry to be weakened or injured in his trip through the maze because
that would make it easier for Voldemort to finish him off. 

Questions regarding theory two: Does canon make it clear who authored
the plan to turn the Cup into a Portkey? If it was Crouch, isn't it a
breach of faith for him to assume Voldemort needs help polishing Harry
off? And if it was Voldemort, wouldn't that be an unusual sign of
self-doubt?  

Thanks in advance for helping me sort this one out.

Lori