Jesus Christ guys, I'm gone for a few months and this trumpets bloke is the best you could find to replace me? What a muppet.
But, to give the OP a fair answer.... You've suggested 29 players from sides in serious trouble.
The first step in building a side capable of avoiding relegation is not to bring in players from sides who have failed to avoid relegation. You should only take the absolute best (note only Turner, Myhill & Hunt gained Premier League contracts after we were relegated)
Al Habsi isn't a bad shout. But then, our first choice keeper is currently Jakupovic, and frankly I'd rather stick my nan in goal than him.
I'm not going to list everyone, but there is precious little that we could really take from Wigan. Figeuroa is a possibility, the rest offer either nothing better than our current options (most of the list) and the remaining players (McCarthy, McCarthur, Kone) will be out of our price range. Not to mention that we're already pretty deep in central midfield.
As for Reading, only really Le Fondre stands out for me. Robson-Kanu has been linked with clubs as high up as Arsenal. Karacan's a good player, but again depth is central midfield is the least of our worries. Kebe is a diving little prick. Pogrebnyak is getting paid. A lot.
QPR aren't all that overpaid, it's been grossly exaggerated in the media. I'd take Jamie Mackie, but I expect him to stick with them.
Sunderland probably won't go down, but I'm not sure I'd be looking at anyone on that list.
Mignolet is looking likely increasingly likely to be Liverpool-bound.
Do the likes of O'Shea, Cattermole etc really offer much improvement? Cattermole is one dirty ****er, I've seen it first hand this season.
Adam Johnson & Sessegnon are obviously good players, but realistically.... no. Even Fletcher & Graham would require unrealistic transfer fees.. and Graham's Sunderland form hardly inspires confidence anyway.
I'm sure you'll jump to the defensive stance of "I'm not talking about who we're getting or who we might go for" but frankly, if you're going to attempt to discuss unrealistic players, well... why bother?
We might as well talk about whether Gerard Pique would improve our back line.