2) is this considered a tax event by irs? if i convert say from usdc to dai, it's just a 1:1 conversion, do i have to report it to irs
Converting from one coin to another are not taxed, only gain are taxed. Like on custodial exchanges like Coinbase, cryptocurrencies are taxed if you spend or sell it having gaining already. If no gain, no tax. Like even converting from stable coin to another stable coin has no gain, so no tax.
I'm not an expert.
In the U.S., a conversion from one token or coin to another is a taxable event. You must report the gain or loss in value of the coin you converted from. Unless you transact in huge amounts, the gains or losses with stablecoins might be too small to report. I think the threshold is $10.
For example, if you buy 10,000 USDC at $0.999 ($9,990) and then convert it all to DAI when USDC is worth $1.001 ($10,010), that's a $20 gain and must be reported.