That's an interesting question; Kindred has supports that they like to have for general gameplay and others that make good comboes. For instance, both Soraka's and Morgana's ults pair amazingly with Kindred's, but they require precise timing and are useless if done wrong, not to mention neither of their regular kits work amazingly with Kindred's.

On the other hand you've got champions like Pyke who plays a really strong lane with Kindred and can work with or without you in lane as an aggressive playmaker that needs to be focused down, but Pykes ult actually clashes with Kindred's unless the Pyke can get that timing exactly right and the Kindred player fully trusts the Pyke.

It honestly depends the most on your own personal playstyle and if you know your support. Most things can work, but I recommend checking the matchup section near the top of the guide for details.

That's a great question, Runtley!

Right in the introduction to the guide it states "The other issue, collecting marks from the jungle, is simple: you don't touch anything in the top half of the map. Marks on Scuttle or Gromp can be simple to collect if you have the chance. You also tend to clear enemy camps during late game, so your marks become an added bonus.".

Additionally farther into the guide under the Gameplay section you have this bit, "Whenever you get the chance, such as when you've killed one or both of your enemies, or they've just backed, check for marks on Gromp, Scuttle or their bottom buff. If there is one, ask your support to follow you and take the mark. It is generally dangerous to go alone, but the two of you could potentially get another kill if you catch the jungler unaware. You can also go alone if you know where the enemy jungler is and you have enough aggressive vision.".

Long story short, you can view marks as mini objectives similar to dragon and Herald; something to collect with the help of your team when you have pressure and/or sufficient vision. Marks are definitely a plus, but are not your end-all, be-all! And once again, if your mark is on a camp such as Raptors or Wolves in the late game but you don't have much time, simply bursting the marked creature can be an option, although Kindred already does a decent amount of AOE damage with her Q, so it's not that drastic of a difference compared to clearing the full camp.