well first of all, thanks for this positive feedback.
as mentioned, 8 new units will be added. but this will take a while.
i dont really get this one... after 1.19 u want even more spells? there are 165 custom abilities in soulchess, i guess about 80%-90% of them are directly used as level 1 / 2 / 3 ability for the units. going beyond level 3 would be wasted effort. again i'd like to mention that every unit-type of every race has unique level 1 2 and 3 (some exceptions let them appear on 2 unit types).
in any case you can be happy as the 8 new units will come with brand new abilities. ive got some really eye-candy ones planned already.
much easier race selection like (DotA Tavren) so we can get info for race picking
theres already basic info displayed if you come near a selection circle. the whole info for the races would never fit into a single tooltip which is the reason i put up large sections for every race in the questmenu. using a tavern is an interesting idea though.... i might even do that. but i cant promise it as it requires more work than you can imagine. and race selection works flawlessly at the moment. the new units simply have priority.
yes, i guess new arenas would be adequate. i hope to get some additional ones done for 1.20.