Hi jeton.
Thank you very much. Great to hear you are enjoying using my app. 🙂
I’ll try to answer all of your questions, but I have to say that the performance of soundseeder on different devices, by different manufaturers and with different versions of android is very hard to predict.

So:
1:
a) The most important factor for the playback performance of soundseeder, is the quality of your wifi signal. When you move around your devices might loose their connection, the streaming buffers run empty and the playback gets out of sync. Make sure your wifi connection is stable and fast.
b) Updating to Android 4.1 can definetely improve the performance of your speakers, yes. Android 4.1 brings an improved audio api and has a much better overall performance than android 2.x and 4.0.
c) Did I relly say “a good Wifi app”? I guess I meant “a good wifi connection” or “a good wifi access point”. (see a)) You can try to improve the connection by using another phone or a wireless wifi router as dedicated portable hotspot to connect your player and speakers. Place the access point in the center of all your devices to get the best connection.

2:
At the moment SoundSeeder uses the default Equalizer of your ROM. I don’t think you can uninstall it to replace it by another EQ. I think you will have to flash a new ROM with a builtin EQ that fits your requirements.
a) I don’t hink so. Dlna/upnp will not help us here…

3:
Sorry but wav files will not be supported soon. You can play them with soundseeder (by selecting them via an external file browser) but the playback will most likely not be in sync.

I do my best to improve soundseeder and I’m planing to add more and more features, so please stay tuned and let me know if you miss anything… 🙂

greets
jens