Overheating, battery drain & Safari crashing 8.4.1 iOS on iPhone 5

Hello, I recently updated my iPhone 5 to iOS 8.4.1. Since then, my device has been running unusually warm during regular use (Safari, Mail, Facebook, Twitter). Background app refresh is always off, but even with the phone on standby (home screen), it continues to generate heat... This leads me to suspect the issue may be network related. My location and device usage has not changed, just the iOS update.

Battery life is also dramatically different now. Today I had to do a full charge every 4-hours (after very minimal usage and screen brightness low). Battery draining was noticeable immediately after installing 8.4.1 Update... Considering how the battery drains even when on standby, I'm again suspecting the issue is network related. (EDIT: until latest update, I could use phone fairly actively all day with only a battery top-up required in late afternoon).

Finally, Safari has become erratic. Certain sites that I usually visit (ex. CBC News) crash Safari, leaving the loading icon spinning and all other buttons unresponsive. Only solution is to double-click home and flick Safari to close. But even after reloading, other websites work fine, but the same website will crash. Not sure if this is related, but Apple Music will also stop streaming songs (at least out loud). Songs stored locally will play fine, but when I click on a song (either by searching or one in an existing playlist) the play icon will engage, and the song will look like it's playing, but no audio will play.

In the last few days, I've tried reseting by holding power & home buttons for 20-seconds until Apple logo appears. This solution has worked temporarily. Safari will work fine on all websites, but then suddenly the same ones (ex. Cbc news) will crash again. Similarly, Apple Music streaming will resume to work correctly and then eventually stop playing audio on the streamed songs.

Last night, I tried wiping the phone completely and then restored from latest backup... all issues persist.

Hesitate wiping phone completely and then starting fresh, rather than restore... Any suggestions before I try that?

Thanks!