Seems like you have a couple of issues, one being a local dealer who isn't doing what you want, and the other an issue with an occasional missfire/starting problem.
If you bought the tractor in Wisconsin, your local dealer may not feel compelled to do things like send you free hoses even though you think he should. I'm NOT saying that is the correct approach, BUT he did not sell the tractor to you, did he?
Therefore you may have to just go exchange the hose with his parts department IF you can get him to agree to do so, or you may have to just pay for the hose. Either way, it's not the best solution, but it gets you the new part eventually.
On the fuel issue, you may well have had a sticking injector, or regen issue or not enough glow time and some coagulated fuel in your filter, or a combination of several of the above.
The newest Kiotis with the Tier 4 equipment have had some bugs on some of the machines related to this type of issue. Unfortunately, more complex fuel systems don't really bode well for smooth running on small tractors. Cleaner air, maybe, except more fuel burnt to make the exhaust cleaner is counterintuitive at best, but it is what the government requires.
You have a long warranty, so feel confident in it and your Kioti. Time and use will tell if you have a problem that needs a fix. In the meantime if a filter jams, I'd discard it vs. trying to get it to work. Once jelling occurs even with PS or similar, it is unlikely to get it clear enough to function as normal, which may have contributed to your issue.
As far as block heaters, you could install one, best in the block, BUT make sure if you do it yourself you do not force out the freeze plug in such a way as to damage the block/liners in any way. One guy on here pushed a tool through and had to remove his entire engine, disassemble it and have it welded. A complete nightmare at best. So either have it done by a professional, or VERY carefully.....