Do the whispers and imaginations that come to me about my husband praising me for my religiosity and good deeds, and my desire for people to praise my good actions without knowing my person, count as showing off (riya') even though I always seek refuge from it and pray to God to protect me from apparent and hidden shirk?

These are whispers from Satan, so continue on the path of righteousness and pay no mind to these thoughts. Beware of abandoning good deeds for fear of showing off (riya'). Rather, your intention that your husband praises his Lord for your obedience is a good intention that does not contradict sincerity. And your desire for people to pray for you, while they are unaware that it is you who performed a good deed, is also something that does not contradict sincerity.

And Allah knows best.