No, it is strictly a training putter.
A solid putting stroke is a solid putting stroke regardless of the putter. The HC5 helps build good pace and tempo, creates muscle memory, and challenges you to hit the sweet spot consistently. All of this practice and improvement translates over to putting with your own putter.
Yes. Simply choose whatever shaft length up to 38 inches and a standard, mid or over-sized grip at no extra cost. The standard length is 34 inches.
The weight of your own putter will feel better since it's one you chose and are used to. Practicing with a training putter that is more difficult, weighs different etc... will instill more confidence when you switch to your own putter. It's not supposed to be easy. Imagine jogging in a pair of boots and then getting to slip on your running shoes!
If someone can consistently make putts with the HC5 that only has a 5 mm wide sweet spot, it seems so much easier with your own putter. It's similar to practicing putting into a 3 inch wide putting cup and then changing to a regulation 4 1/4 inch cup. The perception and sense of confidence created is real. It helps one focus on the contact and not the result.
Yes. The sweet spot has a 3.5 degree loft.
303 stainless steel - similar to many tour level putters.
It is 5 millimeters or .197 inches.