I think so. For starters, he's scored 11 in the Champions League, nothing would change in that regard. Cup games etc..
Also a point is that I watch Barcelona every week, the comments about the league is more open and English teams can defend, I don't 100% agree with, generally English defences defend better but also, every time you watch Barca, it's 10 men behind the ball for the opposition, making it very difficult. Put Messi in the Premiership and you could argue he might at times have more chances because the more space he gets as even if you look at teams in the Premiership, there aren't that many teams, Blues/Stoke etc...that just sit back and take Premiership. Gaps do appear and if there is one player you'd want to exploit those spaces, it'd be Messi. Although obviously Barcelona have a lot more of the ball in world football than anyone else so naturally create more but as you saw.
If Real Madrid played Man United (United having messi) would Real sit back as they much as they did, I don't think so. It could be argued that it'd allow Messi to be given more space to do the thing he did for that second goal, where as tonight, before Pepe got sent off, it was very difficult for him to get on the ball.
Barcelona struggle in the Premiership? I don't think so. People say, Stoke/Blues, they'd struggle. Disagree, 10000%. They wouldn't even get a touch of the ball, they'd barely be able to attack while I'd fancy at some point the likes of Iniesta, Messi, Xavi to open them up. Many defences in Spain play full 10 men behind the ball against Barca, well almost every team has and they've never been successful because they have players who can open up gaps rather than waiting for gaps to form.
You only have to look at the Real team, 4 defenders and then Alonso, Pepe and Diarra all in the middle. Extremely defensive but they are a lot better defensive players than what Stoke/Birmingham have and yet Barca still controlled the match even if they didn't create that much.
Messi himself is one of a kind. He takes kicks week in week out and bounces back. He wouldn't struggle at all, to think that he would despite getting kicked every week, all the time is just daft.