Can hiv increase my chances of dangerous infections?

Potentially: Poorly controlled HIV results in a condition where your own immune system is not capable of fighting off even common viruses and bacteria. So yes, HIV can increase your change of dangerous infections.

Yes: If HIV infection is not treated effectively with antiretroviral chemotherapy it progressively damages the CD4 lymphocytes. Once the CD4 lymphocyte count drops below 200/mm3 the patient becomes susceptible to opportunistic infections. This susceptibility increases as the CD4 count drops further.