Will this (re)emerging conflict fuel a new war and worsen the global economic situation?
According to Wikipedia
Israel suppliers diamonds, refined petroleum, pharmaceuticals, machinery and equipment, medical instruments, computer hardware and software, agricultural products, chemicals, textiles and apparel.While
Palestine exports olives, fruit, vegetables, limestone, citrus, flowers, textiles.
This war will hinder the production and distribution of these goods which will lead to an increase in price. The economy of trading partners of both Israel and Palestine will be negatively affected. This war will also lead to mass refugee crises leading to mass immigration. The economy of neighboring countries will be affected because of pressure on basic infrastructure and an increase in government spending. Allies of both parties will have to use money that would have been invested in key sectors to sponsor this war, which will lead to slow global economic growth. We can't also quantify the loss of human resources. Skilled people that would have contributed to global economy might die or become disabled due to life-threatening injuries.
As to Russia's support of Hamas, I haven't seen any official statements by the Kremlin so far and I have limited access to Russian media but some sources claim that Russians are ridiculing Israel's defensive efforts and are happy to distract US's attention from Ukraine. Iran-backed Hamas seems to get more support from Russia for political reasons.
There are some speculations that Hamas wouldn't have carried out this kind of successful assault without external support. Some political analysts believe Russia might be one of the backers of Hamas. They are assuming that with a war in Israel, US and NATO's attention will be divided meaning that Ukraine will not get the needed support. It's normal to see your enemy suffer defeat, it is not strange to see Russia mock Israel.