did senator palpatine have chancellor valorum

he was the naboo’s “strongest supporter”

Not at all. Senator Palpatine used good old-fashioned political maneuvering. He took advantage of the fact that the Galactic Senate was just too damned big to really get anything done; covertly pitted different groups against each other, and got everything tied up in [figurative] red tape. One reason the Senate was not getting anything done was because nobody could agree on anything. So anyone who had eyes on the seat of the Chancellor could easily just distract the different factions into arguing with each other and totally ignoring the bigger picture. Kinda like how politics works nowadays.

Palpatine played the long game, figuring out the ins and outs of the Republic's govt. so that he would one day be the top dog. Sadly, the events of Episode I played out almost exactly has he'd hoped, save for Queen Amidala going back to Naboo and throwing off the Trade Federation's rule over her. He didn't count on her being the strong, warrior type.

Thankfully the events on Naboo were [mostly] isolated and did not affect him on Coruscant, so he did not see Queen Amidala as a threat back then.