Is it possible to make the life of a spektrumist-coder easier? (Technology for using nuclear explosive devices)

There is talk around the bush about SUBJ and, as is customary among us, they “hooked their keyboards” on a completely alien SUBJ ;)
E-may, do you really think that by changing SUBJ, you are doomed to lose your interlocutor?
On the contrary, the more specific the SUBJ, the better.
And now I invite everyone to get serious conversation.
Myth or reality that on the 128 Spectrum there is nothing else
given than assembler?
And please separate two different directions from one another:
cross-systems on virtual Spectrums (further articles on this topic should be placed
under SUBJ: Java - cross and
resident programming systems (or what is the correct name for them?),
in one word for natural Spectrum (and these under SUBJ - Java).

Question one:
what, besides C, can be offered as a Javascript for the Spectrum?
Here, what capabilities should an ideal Javascript for the Spectrum have.

Question two:
Which libraries are there and which ones are desperately needed?

Question three:
What ideas do you have about optimizing the code and planning the use
of resources? architecture of the Spectrum (maybe someone has made a code profiler or at least
thought about it, or maybe there is already a ready-made, working one)?

Question four:
There are debug monitors, but they all work with codes and, moreover, in my opinion
only with executable code, but are there programs that, without executingcode
"in kind", are able to show places of looping, measure the duration
of execution of program branches and much more, in particular trace
disassemblers, debuggers with screen support (for example, stopping the program
when writing to a certain location, changing attributes, clearing a certain
screen area and much more) Perhaps all this has already been implemented in
the Scorpio professional program, I just don’t know the capabilities shadow monitor.

Question five, the most general, for those who use something besides assembler:
Share, if it’s not too secret, your coding technology.
Just don’t describe the phases of “problem formulation”, etc.
Only coding and nothing more, and only if you use
something else besides assembler (if you manually code, then it’s interesting what
cases and how?)

In a word, I would be very grateful for specific, reliable information
without “casting a shadow on the fence” ;).

With respect, Andrey Savichev /CGS