Why didn't Skynet cover weapons in living human tissue?

Strategic Simplicity: Skynet’s strategy was to send a T-800 back to kill Sarah Connor with a weapon that could be easily obtained in 1984. The T-800 was a weapon in itself, with immense strength and durability, capable of killing with its bare hands if needed. This made the mission less reliant on future technology that might have drawn attention or been difficult to use in an unfamiliar time.

Camouflage and Integration: The T-800 was designed to infiltrate human society, and carrying an advanced weapon might have blown its cover. Using contemporary weapons made it less conspicuous and allowed it to blend in more effectively.

I assume they had limited amount they could send. Cause why not just send ten terminators at once.

Reese told Sarah that Terminators (T-800s) are the perfect killing machines.
so Skynet pretty much just sent one of their dudes thinking it'd be enough.

and it would've been enough.. if it weren't a movie.

Because terminators are infiltrator units! They are supposed to blend in with humans. Can you imagine a man carrying a phased plasma rifle in LA streets and shooting with blazing lasers? People will call the police immediately, on the contrary, if a man carries a gun and shoots people on LA streets, nobody will care.

It’s explained by Reese that the plan by Skynet to send the Terminator back was a desperate, last minute Hail Mary after they’d already lost the war.

As in, they he Resistance had blown their defense grid and were battering down the door as soon as they saw the T800 go through the Time Displacement Equipment. Then they sent Reese through after it and blew the whole place.

One hole in the plot I always considered was the Terminator's power source. If it's running on some kind of nuclear fission reaction, you would think all he'd need to do is get close to Sarah Conner and he could just detonate himself, IMPOSTOR-style.