Questions on 2350LMT/2450LM

Hello, I am upgrading my 255WT that has served me well and will hand over to the Wife for Emergencies. I purchased a competitor but will take it back after realizing what I had in the low end 255 vs theres.

I like the 4.3" but not sure how the junction view will look with that in either the 1490LMT or 2350LMT. I can get a good deal on 2350 for same price as 1490 and I think I can plan routes which was lacking in the 255. I want to spend under 150 USD. I really don't use my GPS much but when I do need it, it does work. And I have taken my 255 on the same 600 mile trip from MD to SC 5 times now and each time it takes me different routes with the same old MAP. Can't figure that out unless it is these updates that push to me. So hear are the questions about 2350

1) Can I 'plan' a route and run a simulation?
2) somehow I got some map viewing software from Garmin that would upload my trip log to my PC, is that available with the 2350?
3) Is it wrong to look at a 2011 model when 2012 is a week away?
4) Is the 4.3" display adequate for junction view? I like the small size of my 4.3 where it does impede my view so I figure the 5" would impede it more.
5) I read where the xx-25 receiver is more sensitive than the xx-35 receiver I think, could I use that if I have a choice? Or am I asking for trouble?

Second Question set 2450LM

Can I use my xx-25 traffic receiver with it? They are offering one for similar price as 2350 without Traffic? Would this be a better deal or am I asking for trouble?

Lastly, Academy sports is offering it for 144 shipped, is that still a fair price or do you see it dropping drastically at beginning of the year?

Thank You