If that's what you are using VB6 for, your code sucks. None of those three items have been a best practice.
I have a 25 KLOC program that converted completely, and runs without changes. The VB.NET upgrade wizard for VB6 worked perfectly. Of course, that won't be the case with all programs, but for many mainstream, conservative programs, it will be.
Dear child, the use of various legal language statements doesn't make one's code "suck" (I can even point to lots of code that fails to use those statements that aren't worth spitting on), nor is it the fault of programmers who use the 60% of VB 6 that is no longer compatible with VB.Net.
One major reason to use the Goto command is in establishing VB 6 error detection and correction routines. For VB.Net the entire error handling system has been forcefully changed, with the old VB 6 method no longer supported BY DESIGN.
I don't like your Blame the Victim mentality. It goes to the heart of why people such as yourself should remain unemployed and bitter.
If the shoe was on the other foot, and Sun came out with a Java compiler or interpreter that didn't support 60% of legacy code from previous versions of Java, you and people with your child-like mindset would be cheering in the streets at how Sun wasn't smart-enough to make a backwards compatible compiler.
Likewise, no one would cheer a new C++ compiler that couldn't compile 60% of existing C++ code, yet that's what you are trying to do when you pretend that it isn't Microsoft's fault that VB.Net will only compile 40% of existing VB 6 code.
Why, if your code wasn't compiled, then it must be your fault, your silly mind blurts out. Your code must suck.
Sigh. Corporate America doesn't need such technical Yes-Men. We've already got too many of those in management.
Oh, and by the way, your claim at the top of this post is balderdash. If you needed to "convert" your 25,000 LOC VB 6 program in order to get the VB.Net environment to accept it, then by definition your code has had changes made to it (in stark contrast to your amatuerish cries that your code didn't need "changes").
In any Mission Critical environment running any formal testing methodology, those changes alone (in the conversion) would mandate full-scale system-level re-testing.