Guys i have few suggestions..
1) lag,fc,reboot:- use ftf flashing with wiping options enabled, if u use recovery flashing, do data factory reset before flashing. Also odex firmwares are speedy than deodex ones.. And alo remb to delete "data and android" folders from sd card too..( but u can backup and reuse data which are big, like game data files)
2:- camera probs :- check ur sd speed if u save pics in sd, recommended speeds are class 6, to u1, not needed u2 or extreme cards above 40mb/s rw.
Or just save pics to internal, and move to external when needed.
Sd card are not simple things, random rw to sd drains battery much more rapid, may slow down s/m and so on..
3) reboots and networks:- use default kernal or moded ones, which are derived from same region ftf's, ie if u use euro version ftf, euro version kernel is recomended and not others ( especially if u face network probs)
4)battery:- use of messaging apps, social networking apps, widgets, antivirus, etc it will drain battery quick, also most battery savers have opposite effects on batter, as they run as services, instead if u are rooted, i recomend greenify app, also turn off location finding using wifi and mobile data, insted use gps! ( ya.. I said gps, why? Coz it does turn on only when wanted, but in case of wifi or mobile, it usually syncs with network to retrive location data), another one- use manual brightness set at lowest when u are inside room most time, and just turn on automatic when outside..
Turn off haptic feedbacks and click sounds, keep the volume as much as u want..
May this things will help
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