Hoo boy... Three questions I could talk about for an hour on each easy.
1. Software is a very
broad topic and comes down to personal preference most frequently on what people say is useful. The three easy categories to break everything down into are Design Suites
, Repair Tools
, Scaling Tools
Design Suites are software packages to build your own models or modify existing ones. There's dozens of free options out there all geared to different users and their needs but the ones I use frequently and recommend are Blender, Fusion 360, Meshmixer and SketchUp. Like I said, each has it's different use but I often find myself bouncing between two or three during a project to make the best use of each suites power to speed up my workflow.
Repair Tools make it so that your design is usable on multiple printers. Sometimes my Slicer doesn't pick up errors in files that other people will encounter so I run models through either Azure
, SketchUp Solid Inspector or Trinckle
to clean up any funny geometry that may throw others for a loop.
Scaling Tools are what you use to make sure that everything will fit onto your body. Armorsmith Designer by Armoured Garage is a fantastic program to dress an avatar .obj file of yourself and make sure pieces are wearable and scaled to each other.
Slicers produce GCode to instruct your printer how to operate. This is entirely a personal preference or based on your machine if it uses proprietary software. I like to use Cura or Repetier but there are more powerful (paid) options available.
2. Machines break, lose calibration due to motion and mistakes happen causing failed prints by human error. Yes there are more reliable machines but nothing is 100% success rates and many aren't even 80% fresh out of the box if you've never built and run a printer before. My reliable workhorse machine is a Wanhao Duplicator i3 V2.1 and my more temperamental but quicker/bigger printer is a Tevo Tornado. Both have modifications done to them to increase ease of use and reliability and both have thousands of hours and dozens of spools of filament run through them.
3. My first machine which has been sold off was touted as a beginner friendly machine (M3D Micro) which was great for learning but overall not at all useful for props and armour because of a lot
of proprietary and specialty pieces. Open source and easy replacement parts is a way of life.