-ava, not a slavic suffix?

Hi together,

Teh suffix -ava was considered to be a slavic one.
There are some facts which shows this suffix is older as
assumed:
in the celtic region we find as fallow:
-Masava vicus , today Mesves-sur-Loire
-Masavo, today Manchester
-Ammava, Antonnava, Apava (Bordeaux), Ariava, Belenava,
Corbava, Genava(Genev), Norava

in the thracian space:
-Sava, Berzava ( I know Sava appears for first time recorded
at 372 AC)

In the rum.language this old suffix is supposed to have the
form -av,-ov,-iv for masculine and -ava,-ova,-iva for feminine
I will give some where the root is supposed to to come from
slavic words:
-gângav = person which speak hardly, uninteligible ( < sl.
gongnavU)
-bolnav = to be sick, ill (<bulgarian bolnav)
-firav = with a fragile structure, fragile ( < sl. chyravU)
-hulpav= a big eater ( <bulgarian hlapam or < serbian hlapiti)


So, after all this I should like to ask:
- is now indeed this suffix "-ava" slavic or not?
-are the words "hlapam, hlapiti, chyravU, gongavU, bolnav)
still to find in the actual slavic languages?
-there are rumors the -av for masculine ,-ava for feminine
should be just the thracic and celtic correspondent of latin
suffix "-ivus". What do you think about?