What your doing seems to be ok and more respectful than most I’ve observed.
Although many people don’t even see it, there is usually a Crucifix behind the Altar, so your not bowing to nothing.
If I walk past the Tabernacle which I usually have to do during the collection, the I genuflect.
I go in, bless myself, walk to the pew, genuflect and kneel and say a few prayers before Mass begins, what you do is ok too, I’d suffer people not doing any of it if they’d just stay quiet.
Leaving I genuflect, walk to the font and bless myself and on my way.
Some go-to the Statue of Saint Teresa and touch the Crucifix she is holding and bless themselves, before leaving the Church.
Not relevant to your situation I know but some kiss the crucifix before and after the Rosary, I do, and some don’t.
I’m sure as long as it isn’t irreverence your showing then don’t get too concerned, some things are written in stone, but I don’t think you’ll be shot at dawn if you make a mistake.
Keep in mind that your in Gods house and your genuflections are aimed towards God, regardless of whether we can see Him or not.
I know some of out newly acquired Polish congregation kneel on the floor and bow as the just enter the Church.