Can a 3.3v logic i2c be directly connected to 5v logic i2c
Don't build a product to sell like you described, but if you are playing around with a home project, it will work well enough to get by.
I use MSP430 MCUs with 3.3V IO with 5V I2C LCD displays. I had to remove the 5V pull-ups on the LCD PWB and add my own 3.3V pullups. Works fine.
Worst case CMOS logic high is 70%, but a typical part switches close to 50%. 70% of 5V is 3.5V, 50% is 2.5V.