There is so much wrong with this thread that it's mind boggling.
I have no idea why you think trying to force some random statement into an expression is going to make things faster, but it's really not. Trying to play tricky games with a language that compiles to an intermediate bytecode is also just laughably futile.
Furthermore, C# * absolutely* can be inlined, but you're not going to find it on the IL level, since it's a feature that's handled by the JIT and the CLR. It's also probably going to be a lot smarter about when to do it than you would be, taking into account the adverse affects it can have on polluting the instruction cache and potentially spilling registers in tight loops.
Additionally, boxing and unboxing are not going to have much of a performance hit on your application unless you're doing a ton of them. Allocations in a garbage collected environment are very fast, and small short-lived temporary objects are one of the best-case scenarios for the typical managed GC. It's unlikely to cause any fragmentation problems, considering that the GC moves objects in memory to avoid that very issue.
It's also not difficult to avoid boxing calls. Your nine thousand line program is actually pretty small as far as most games go, and it's absolutely possibly to avoid any boxing operations in a code length of that size, depending on what you're doing. As Frob said, if you find yourself needing to do it often, you need to critically rethink your design.
Despite all that, if you actually needed every single cycle available to you (and I'm not convinced that in your case you do), you should be working in a language that facilitates that kind of development, such as C++. Probably you're going to keep misguidedly doing what you're doing, but if nothing else this post should help others who might stumble upon this thread.
Edited by Mike.Popoloski, 24 May 2013 - 11:49 PM.