More DRAM questions: vias and trace lengths.

[technix]

Background: datasheets and user manuals: SoC is NXP i.MX233 in LQFP128 (combined datasheet and user manual,) layout guide here. DRAM is Micron MT46V32M16TG-6T.

I am trying to hook up those, and still have some problems with the high speed signals and routing. The pinout on the i.MX233 is intended to be used with the FBGA variant of DDR memory, however most local vendors I searched for carries only the TSSOP version. I have tried to fit the TSOP memory chip with the application processor, but even with byte swapping and bit lane swapping I ended up getting kind of a mess when not using vias - the DQM signals have to loop around the entire DRAM chip... definitely not a good idea even with delay compensation, and the clock signals also have to loop a bit. Do keep in mind that i.MX233 have built-in delay buffers to compensate the trace length mismatches, so length is less important than via count at least according to the layout guide. Questions:

* How fast is the rise and fall edges of the DDR-333 SSTL-2 memory bus in the first place? This is linked to the trace length calculation but it is nowhere mentioned in either datasheet.
* It seem to me that using 2 vias for all memory bus traces seem to be a good idea here. Is it really?
* Is a sharp turning corner at the via going to bite me? (For example, the trace runs up to a via, drops to the bottom layer and immediately goes down.)

A few general questions about the design:

* In your opinion, which is more important for a DIY tablet/digital picture frame: a microSD card slot, or a network connection? i.MX233 have only two SDIO interfaces, one of which is occupied by the NAND chip through pinmux. (I have industrial-grade NAND chips - see below) Now for the remaining SDIO interface I can either connect it to a microSD card slot or an SDIO Wi-Fi module. Personally I prefer the network connection variant since once the kernel is up it can make use of the network connection to pull data off the cloud and I can SSH into it, but without microSD card slot I may have troubles getting it to boot the first time and load the kernel. Or how do I construct a SDIO mux properly with the kernel in mind?
* Am I pushing it with 800x480 resolution through the chip and the EPM240T100C5N CPLD demultiplexing the signal? Or do I need a faster CPLD? Or am I overclocking the i.MX233's LCD interface? (I have heard of people pushing 800x480 from i.MX233 from Olimex, but that uses non-multiplexed RGB LCD interface.)
* Since the SoC I bought are industrial grade chips, is it better for me to prefer all other parts to be industrial-grade or better? (My recent grab bag included some automotive-grade parts - are those better than industrial?)