Well, I understand that facing SOV in mid '45 is a nightmare but it's very very far in the game. I feel that most of the game has already been decided somewhere else when SOV hordes arrive.
Of course they are a problem, but if you have USA strat bombing your industry at short range and no more industrial power... Well you are done in any case.
On the other side, if you are somehow holding the ground in mid '45, SOV will cause you a lot of troubles but you can try to slow them down for some months.
Regarding China: raw AVs are not very indicative. Good Chinese troops are a big problem but they still lack of heavy equipement and there is no way they can have sufficient supplies just holding CK plains.
Those damn cities provide them some industrial power but it's nothing that changes the balance in the Theatre.
India. It's horribly complex to attack India. I landed there at the end of January and I still had to conquer Burma so it has been a very brutal campaign with thousands of squad destroyed and many LCUs razed.
Moreover, I have been blocked around Calcutta for 4 months.
Therefore, I do not advice to attack India unless you are so sure of what you are doing that you can bear the burden of months and months of terrible losses everywhere.
On the other side, now that I am besieging Hyderabad and Bombay with just USA reinforcements to contest me, I feel that attacking India is a big deal. Well, 'big' is an euphemism...
Securing India provides a lot of OIL (300 undamaged from Magwe and 70 from Ledo), RES, HI and LI. And, something very important, it blows up Commonwealth's armies: they have a chronic shortage of everything and if you destroy some divisions leaving the others barely alive, it becomes really difficoult for an Allied player to gather a threatening force for a very long time.
I decided to bet on India rather than other places and I am completely satisfied with my choice, even if very bloody (in August I have used 800 IJA inf squads for example).