I agree that Fire/Water is probably one of the most balanced out of Fire's elemental counterparts but everything else is very debatable. Fire/Tai isn't exactly stronger than Light/Tai. That's very debatable.
Tai light has homings, and stuns paired with the ability to interrupt everything from their Taijutsu half. Yes with Fire/Tai you can get off some damage with a knock back into phoenix/dragon but this also leaves you vulnerable where as though a tai light has better tools to set up combo's in its kit without being punished.
"Fire/Water > Light/Water" is also very debatable. It depends on the match up. Fire/Water has no good combo starter aside from water prison. Other than that the Fire/Water mastery depends on aim for the most part. Light/Water how ever has multiple combo starters with Spear/Chidori/WP and even has a better interrupt like lightning current which is far better than vortex and less punishable than big flame bullet. I personally think Light/Water is better and easier to use. However that is just an opinion ofcourse, it's very debatable.
"Fire/Earth > Light/Earth" in groups I would give fire/earth the edge, but in 1v1? no. Honestly you can save Earth wall to block phoenix if you feel like you may get hit (or flat out dodge it, it's not hard to). Dragon is a good burst damage jutsu but it's easily punishable. Which is fair, high risk high reward however the opposing mastery can easily punish this. Light/Earth also like the former mastery combo has a far better combo starter and much more options. You also have the earth homing which is only 14 second cool down and continuously poke them.
This despite what people think is not 100% a fact. It does have very good burst damage jutsu's but it isn't the highest. INT Wind has better base damage for a lot of it's jutsu. There's also jutsu like explosive kunai that hit twice while also applying burn. Poison jutsu's also tick longer than burn while also doing more damage with only slightly less base damage which will usually amount in more damage over time than fire would.