Hey guys, I’m proud to be here with you on this Blender forum. I just started using Blender after 2 years of 3ds Max and I am extremely impressed with it! 
I just have a couple of questions for people who know Blender’s features in-depth.
I do some modeling of aircraft used for flight simulators, and I learned 90% of what I know about 3ds Max from other flight sim developers. I’m very familiar with Max’s tools after using them for so long, and that’s where I’m having some trouble with Blender.
You see, in 3ds Max there is a tool called “Weld” that will either collapse 2 vertices together, or you can also highlight a region of verts and weld all of them within a set distance of one another, otherwise known as a weld threshold. (You guys probably know this, but I’m just making sure.) In Blender, I am using the “Merge” tool for my vertices. I like the fact that you can target a cluster of verts to collapse on a single one, which isn’t possible in Max. I thought that was pretty cool. But I’m not seeing a tool like the weld threshold to “mass-weld” my model (I detached some parts and then re-attached them, so there are multiple vertices floating in the exact same space.) I’d like to know how to achieve this if possible.
My other question is about smoothing groups–In most 3D programs you can assign sets of polygons on an object to different smoothing categories without splitting edges to form sharp corners. You can also smooth the whole object with a face angle threshold, say 30 degrees, so any polygons meeting at an angle of 30 degrees or less are smoothed together, while faces meeting at angles of more than 30 degrees are kept un-smoothed to retain sharp corners where the user wants them. Once again, I’m not seeing this option in Blender.
So if anybody knows the secrets to achieve these effects, please reply. Thanks in advance!
Failing that, the forums are extremely active so ask away.