Occupations across 30 years

[Harold Silander]

Would someone be able to interpret some things that I have found during my research?
 
I am not quoting the Genline references, but I can provide them if it would be useful.
 
My great grandfather was born in Halland in 1847 and moved to Gothenburg in 1868. On the moving-in record he is described as Yngling, I think, which merely means youth, I think?
 
He lives in Gothenburg, marries in 1875, has a family and is described in the HFLs as månadskarl. I found an answer somewhere in Anbytaforum - En månadskarl är/var en arbetskarl som anställdes per månad - a labourer hired on a monthly basis?
 
Now the puzzle.
 
His wife dies in 1891 and he re-marries in 1892, a lady from Halland. They have a son.  
 
During 1894 the whole family breaks up - my ggf/wife/son return to Halland, my gf emigrates to Scotland, my gf's siblings spread out, even his 8 year-old sister remains in Gothenburg with an aunt.
 
In this final Gothenburg HFL, my ggf's occupation of månadskarl is crossed out and replaced by f. Inspektor.
 
Later, in Halland, he is Hyresgäster (tenant?) in Gården 24 och 25, and is f.d. Inspektor.
 
Finally, when my grandfather married in Scotland, he recorded his father's occupation as carter.
 
My question is really about the different occupations. What was an Inspektor, is månadskarl likely to include carter?
 
Secondly, it looks like he retired in 1894, age 47??? Maybe his second wife had money? But to leave his 8 year-old daughter behind with his first wife's sister???
 
Any explanations welcomed. Many thanks.