Here is the answer.
1) "RISC" stands for "Reduced Instruction Set Computer". It is the computer architecture where usage of pipelining is used to simulate the instruction parallelism (executing more than one instruction at a time).
2) Few examples of advantages are faster execution of instructions, greater portability to the next version, and the general simplicity of RISC.
3) The problem discussed in the webpage was the hazards. The example of the hazard is when executing data in out of order, creating a wrong data result than what the instructions intended to be. Executing out of order can be possible due to pipeline architecture.
4) False, the sequestial execution means instructions are handled one at a time. Look under the Terminology.
5) Stalls are mainly used to avoid the hazards caused by pipeline architectures. Since stalls takes up a execution time, it is undesireable to have them; but it is sometimes the only way to execute the data correctly.