No, the kit is an additional option. But without it, the heat gets in and makes the AC less efficient.

yes, normal CH plug on it

The warranty extension can also be purchased after the purchase, at any time during the normal warranty period (but before expiry and before the first service case).

The drain hose is included only for the cooling function. For the heating function, the necessary hose (larger diameter) must be purchased; they are available from DIY stores.